add astro-tests

G4:G431/CORDIC/Readme.md

@@ -0,0 +1,241 @@
+# STM32 Astronomy & CORDIC Test Project
+
+## Introduction
+
+This project is designed for **STM32G4** microcontrollers (specifically the STM32G431) and provides a
+framework for:
+
+- **Astronomical coordinate transformations** (Alt-Az vs HA-Dec, RA/HA, Local Sidereal Time).
+- **Atmospheric refraction** modelling using a single-precision adaptation of SOFA/ERFA algorithms.
+- **Performance comparison** between standard `math.h` functions and the hardware-accelerated **CORDIC** unit 
+  built into the STM32G4.
+- **Interactive control** via a serial (UART) command interface.
+- **Precise timing** measurements using a 32-bit timer.
+
+All calculations are performed in **single-precision floating-point** for speed on microcontrollers without 
+hardware double-precision support.
+
+---
+
+## Hardware Platform
+
+- **MCU**: STM32G431 (or any STM32G4 with CORDIC).
+- **Clock**: HSE oscillator, system frequency defined by `SysFreq` (usually 170 MHz).
+- **GPIO**:
+  - **PC6** - LED (active high).
+  - **PC13** - User button (pull-down, pressed = high).
+- **USART1**:
+  - **PA9** - TX (alternate function 7).
+  - **PA10** - RX (alternate function 7).
+- **Timers**:
+  - **SysTick** - 1-ms system tick (`Tms`).
+  - **TIM2** - 32-bit counter running at 1-MHz for microsecond measurements.
+
+---
+
+## Building and Flashing
+
+The project is intended for use with **GCC ARM** toolchain. Key build definitions:
+
+- `SysFreq` - system clock frequency in Hz (e.g., 170000000).
+- `BUILD_NUMBER` and `BUILD_DATE` are defined in `version.inc` (generated by `make`).
+
+Flashing can be done via SWD using st-link (`make flash`), via DFU (`make dfuboot`) or via USART1 bootloader
+(`make boot`).
+
+---
+
+## Software Architecture
+
+The system runs an infinite loop in `main()` that:
+- Services the UART (receiving and sending data).
+- Parses incoming commands via `parse_cmd()`.
+- Blinks the LED every 500 ms.
+- Detects button presses and measures press/release duration using TIM2.
+
+---
+
+## Module Descriptions
+
+### 1. `hardware.c/h` - Low-level initialisation
+
+- `gpio_setup()`: configures GPIOs, enables SysTick (1 ms interrupt), and initialises TIM2 for microsecond counting.
+- Provides macros for LED and key handling:
+  - `LED_ON()`, `LED_OFF()`, `LED_TOGG()`
+  - `KEY_PRESSED()` - returns true if PC13 is high.
+- `timer_start()`, `timer_stop()`, `timer_read()` - control TIM2 for precise time measurements.
+
+### 2. `usart.c/h` - UART1 with DMA and ring buffers
+
+- Uses **circular DMA** for RX and **normal DMA** for TX.
+- RX buffer size: 256 bytes (DMA) + 512 bytes (ring buffer).
+- TX buffer size: 512 bytes (ring buffer) + 256 bytes (DMA).
+- Interrupts:
+  - USART1 interrupt - detects end-of-line (`\n`) and triggers line processing.
+  - DMA1 Channel 1 (RX) - handles receive error (buffer overflow).
+  - DMA1 Channel 2 (TX) - signals transmit completion.
+- Functions:
+  - `usart_setup(uint32_t baud)` - initialises UART at the given baud rate.
+  - `usart_sendstr(const char*)` - queues a string for transmission.
+  - `usart_getline()` - returns a pointer to a null-terminated buffer containing one line (ends with `\n`), or `NULL` if no complete line.
+  - `usart_process()` - must be called frequently to feed the TX buffer and move RX data from DMA to the ring buffer; returns status flags.
+
+### 3. `commproto.cpp` - Command protocol
+
+- Parses commands of the form:
+  ```
+  command [args] [= value]
+  ```
+- Built-in commands and variables (see **Usage** below).
+- Uses a **hash table** (compile-time hashing) to dispatch commands efficiently.
+- Supports **getter** and **setter** for floating-point variables (az, dec, ha, ra, zd, humid, press, temp).
+- Command results are sent back via the UART send function.
+- Error codes are defined in `commproto.h`.
+
+### 4. `astro.c/h` - Astronomical calculations
+
+All angles are in **degrees** unless otherwise noted.
+
+- **Time**:
+  - `MJD_from_unix(uint32_t t)` - converts Unix time (seconds since 1970-01-01) to Modified Julian Date (MJD).
+  - `LST_from_unix(uint32_t t)` - computes Local Sidereal Time (in hours) for the observer's longitude (`long_hrs`).
+- **Coordinate transformations**:
+  - `altaz_to_hadec()` - convert Alt-Az to HA-Dec.
+  - `hadec_to_altaz()` - convert HA-Dec to Alt-Az.
+  - `ha_to_ra()` and `ra_to_ha()` - convert between Hour Angle and Right Ascension given LST.
+- **Refraction** (single-precision adaptation of ERFA `eraRefco`):
+  - `refco_f32(float P, float T, float RH, float wavelength, float *refa, float *refb)` - computes A and B coefficients for the refraction model:  
+    `dz = A*tan(z) + B*tan(z)^3` (z = zenith distance).
+  - `refraction(float P, float T, float RH, float zd)` - returns the refraction correction in degrees.
+- The observer's **latitude** and **longitude** are fixed in the code (`lat_rad` and `long_hrs`). They may be changed by editing `astro.c`.
+
+### 5. `cordic.c/h` - Hardware CORDIC wrappers
+
+- Interfaces with the STM32G4 CORDIC coprocessor.
+- Functions:
+  - `cordic_sincos(float angle, float *sin, float *cos)` - computes sine and cosine in one call.
+  - `cordic_sin(float angle)`, `cordic_cos(float angle)` - individual functions.
+  - `cordic_atan(float x)` - returns atan(x), x in [-1,1].
+  - `cordic_sqrt(float x)` - returns sqrt(x) for x > 0.
+  - `cordic_log(float x)` - returns natural logarithm of x (x > 0).
+- **Precision**: Q1.31 fixed-point (32-bit) with 5 iterations (`CORDIC_CSR_PRECISION = 5`).
+- Input scaling and normalisation are handled inside each function.
+
+### 6. `strfunc.c/h` - String utilities
+
+- Number formatting:
+  - `u2str()`, `i2str()`, `uhex2str()` - convert integers to strings.
+  - `float2str(float x, uint8_t prec)` - convert float to a compact string with optional scientific notation.
+- Number parsing:
+  - `getnum()`, `getint()`, `getfloat()` - parse numbers (decimal, hex, binary, signed, floating with exponent).
+- `omit_spaces()` - skip leading whitespace.
+
+### 7. `ringbuffer.c/h` - Circular buffer
+
+- Generic ring buffer for arbitrary data.
+- Functions:
+  - `RB_write()`, `RB_read()`, `RB_readto()` (read until a delimiter), `RB_hasbyte()`, `RB_datalen()`, `RB_clearbuf()`.
+
+### 8. `test.c/h` - Performance tests
+
+- Runs a fixed number of iterations (`N_TESTS = 1000`) on random data.
+- Measures execution time using TIM2 (microseconds).
+- Tests available:
+  - `math` functions: `sinf`, `cosf`, `atanf`, `sqrtf`, `logf`.
+  - `CORDIC` functions: `sincos`, `sin`, `cos`, `atan`, `sqrt`, `log`.
+  - **Astronomy** tests:
+    - Coordinate transformations (Alt-Az vs HA-Dec) - measures time per conversion.
+    - Refraction cycle (ha-dec to alt-az, apply refraction and convert back) - includes `refraction()`.
+    - LST calculation - measures time per LST computation.
+
+---
+
+## Usage: UART Commands
+
+Connect to the USART1 (default baud rate **115200**, 8N1) using a terminal program. The device echoes
+responses to commands.
+
+General syntax:
+```
+command [args] [= value]
+```
+- Without `= value`, the command acts as a **getter** (prints current value) or command that don't needs
+  argument.
+- With `= value`, it acts as a **setter**.
+
+All floating-point values are printed with 7 decimal places.
+
+### Available Commands
+
+| Command | Description |
+|---------|-------------|
+| `help` | Show this help message. |
+| `testtimer` | Test the microsecond timer for 1 second (prints elapsed us). |
+| `testc = <func>` | Test CORDIC function: `sincos`, `sin`, `cos`, `atan`, `sqrt`, `log`. Prints time in us. |
+| `testm = <func>` | Test `math.h` function: `sin`, `cos`, `atan`, `sqrt`, `log`. Prints time in us. |
+| `sincos = <angle>` | Compute sin/cos for given angle (degrees) using both `math.h` and CORDIC, print results. |
+| `testastro = <func>` | Test astronomy functions: `coords` (transform cycle), `lst` (LST calculation), `refr` (refraction cycle). Prints time in us and ms. |
+| `sets [= 0/1]` | Choose sine/cos implementation: `0` = `math.h`, `1` = CORDIC. |
+| `time [= unix_sec]` | Show current Unix time, MJD, and LST. If `= unix_sec` is given, sets the system time. |
+| `az [= value]` | Azimuth (degrees, -180..180). |
+| `dec [= value]` | Declination (degrees, -90..90). |
+| `ha [= value]` | Hour Angle (degrees, -180..180). |
+| `ra [= value]` | Right Ascension (degrees, 0..360). |
+| `zd [= value]` | Zenith Distance (degrees, 0..90). |
+| `humid [= value]` | Relative humidity (0..1). |
+| `press [= value]` | Atmospheric pressure (hPa, 0..1200). |
+| `temp [= value]` | Temperature (degC, -273.15..100). |
+| `hara = 0/1` | Convert HA to RA (`0`) or RA to HA (`1`) using current LST. Updates the corresponding variable. |
+| `azhd = 0/1` | Convert Alt-Az to HA-Dec (`0`) or HA-Dec to Alt-Az (`1`). Updates relevant variables (az, zd or ha, dec, ra). |
+| `refr` | Compute refraction (arcseconds) for current `zd`, pressure, temperature, humidity. Also prints A/B coefficients. |
+
+**Note**: The `azhd` and `hara` commands automatically use the current system time (from the last `time` setter) to compute LST.
+
+---
+
+## Testing and Performance
+
+The test commands (`testc`, `testm`, `testastro`) measure execution time over 1000 iterations on random input
+data. This allows you to compare the speed of hardware CORDIC against software `math.h` and evaluate the
+overall efficiency of the astronomical pipeline.
+
+Example outputs (typical for STM32G4 @ 170 MHz):
+
+```
+testc = sincos
+TIMEus=425
+```
+
+```
+testm = sin
+TIMEus=884
+```
+
+```
+testastro = coords
+TIMEus=159680
+TIMEms=159
+```
+
+These numbers help in optimising real-time applications such as telescope control.
+
+---
+
+## Notes and Customisation
+
+- **Observer coordinates**: The latitude (43.6535278deg) and longitude (41.44143375deg) are hard-coded in
+  `astro.c` as `lat_rad` and `long_hrs`. Modify these for your location.
+- **CORDIC precision**: The number of iterations is set to 5 (`CORDIC_CSR_DEF`). You can increase it for 
+  better accuracy at the cost of speed.
+- **Refraction model**: The model works best for zenith distances up to ~80deg. It uses a wavelength of 
+  0.55um (optical) by default.
+- **Baud rate**: Default is 115200. Change the argument to `usart_setup()` in `main()` if needed.
+- **DMA buffers**: Sizes are defined in `usart.h`. Adjust if you experience overruns.
+
+---
+
+## License
+
+This project is released under the **GNU General Public License v3**. See the header of each source file for 
+details.
+

G4:G431/CORDIC/cordic.files

@@ -1,3 +1,4 @@
+Readme.md
 astro.c
 astro.h
 commproto.cpp

G4:G431/CORDIC/hardware.c

@@ -28,24 +28,12 @@ void sys_tick_handler(){
 }
 
 static void timer_setup(){
-    RCC->APB1ENR1 |= RCC_APB1ENR1_TIM3EN;
+    RCC->APB1ENR1 |= RCC_APB1ENR1_TIM2EN;
     __DSB();
-    TIM3->CR1 = 0;              // disable counter
+    TIM2->CR1 = 0;              // disable counter
-    TIM3->PSC = 84;             // 85 MHz / 85 = 1 MHz
+    TIM2->PSC = 84;             // 85 MHz / 85 = 1 MHz
-    TIM3->ARR = 0xFFFFFFFF;     // 32-bit auto-reload (maximum)
+    TIM2->ARR = 0xFFFFFFFF;     // 32-bit auto-reload (maximum)
-}
+    TIM2->EGR = TIM_EGR_UG;
-
-void timer_start(){
-    TIM3->CNT = 0;
-    TIM3->CR1 = TIM_CR1_CEN;
-}
-
-void timer_stop(){
-    TIM3->CR1 = 0;
-}
-
-uint32_t timer_read(){
-    return TIM3->CNT;
 }
 
 void gpio_setup(){
@@ -62,7 +50,7 @@ void gpio_setup(){
     // count milliseconds
     SysTick_Config(SysFreq / 1000);
 
-    // Setup TIM3 for microsecond counting
+    // Setup 32-bit TIM2 for microsecond counting
     timer_setup();
 }
 

G4:G431/CORDIC/hardware.h

@@ -18,6 +18,8 @@
 
 #pragma once
 
+#include <stm32g4.h>
+
 // KEY (intpullup->0) - PC13
 // LED - PC6
 #define KEY_PORT    GPIOC
@@ -38,6 +40,15 @@ extern volatile uint32_t Tms;
 
 void gpio_setup();
 
-void timer_start();
+TRUE_INLINE void timer_start(){
-void timer_stop();
+    TIM2->CNT = 0;
-uint32_t timer_read();
+    TIM2->CR1 = TIM_CR1_CEN;
+}
+
+TRUE_INLINE void timer_stop(){
+    TIM2->CR1 = 0;
+}
+
+TRUE_INLINE uint32_t timer_read(){
+    return TIM2->CNT;
+}

G4:G431/CORDIC/test.c

@@ -20,6 +20,7 @@
 #include <stdint.h>
 #include <stm32g4.h>
 
+#include "astro.h"
 #include "test.h"
 #include "hardware.h"
 #include "cordic.h"
@@ -90,38 +91,95 @@ static uint32_t run_test2(void (*gen)(), void (*func)(float, float*, float*)){
 }
 
 // ------------- math.h tests -------------
-uint32_t test_math_sin(){
+uint32_t test_math_sin(){ // 0.9us per cycle
     return run_test(fill_random_sin_cos, sinf);
 }
-uint32_t test_math_cos(){
+uint32_t test_math_cos(){ // 0.9us per cycle
     return run_test(fill_random_sin_cos, cosf);
 }
-uint32_t test_math_atan(){
+uint32_t test_math_atan(){ // 0.9us per cycle
     return run_test(fill_random_atan, atanf);
 }
-uint32_t test_math_sqrt(){
+uint32_t test_math_sqrt(){ // 0.16us per cycle
     return run_test(fill_random_sqrt, sqrtf);
 }
-uint32_t test_math_log(){
+uint32_t test_math_log(){ // 0.9us per cycle
     return run_test(fill_random_log, logf);
 }
 
 // ------------- CORDIC tests -------------
-uint32_t test_cordic_sincos(){
+uint32_t test_cordic_sincos(){ // 0.4us per cycle
     return run_test2(fill_random_sin_cos, cordic_sincos);
 }
-uint32_t test_cordic_sin(){
+uint32_t test_cordic_sin(){ // 0.4us per cycle
     return run_test(fill_random_sin_cos, cordic_sin);
 }
-uint32_t test_cordic_cos(){
+uint32_t test_cordic_cos(){ // 0.4us per cycle
     return run_test(fill_random_sin_cos, cordic_cos);
 }
-uint32_t test_cordic_atan(){
+uint32_t test_cordic_atan(){ // 0.12us per cycle
     return run_test(fill_random_atan, cordic_atan);
 }
-uint32_t test_cordic_sqrt(){
+uint32_t test_cordic_sqrt(){ // 0.4us per cycle
     return run_test(fill_random_sqrt, cordic_sqrt);
 }
-uint32_t test_cordic_log(){
+uint32_t test_cordic_log(){ // 0.4us per cycle
     return run_test(fill_random_log, cordic_log);
 }
+
+// ------------- Astronomy tests -------------
+// test coordinates transformation: hor2eq and eq2hor
+uint32_t test_astro_coordsTransform(){
+    volatile float az = 11.3f, alt = 89.3f, ha, dec;
+    timer_start();
+    for(int i = 0; i < N_TESTS; ++i){
+        // 160us per cycle for math.h sin/cos
+        // 15us per cycle for CORDIC sin/cos
+        altaz_to_hadec(alt, az, (float*)&ha, (float*)&dec);
+        hadec_to_altaz(ha, dec, (float*)&alt, (float*)&az);
+        if((az += 9.51f) > 359.99f) az -= 359.9f;
+        if((alt -= 1.76f) < 9.9f) alt += 79.f;
+        (void) ha;
+        (void) dec;
+    }
+    timer_stop();
+    return timer_read();
+}
+
+// test refraction correction for HA-DEC (eq2hor->refr->hor2eq)
+uint32_t test_astro_refraction(){
+    float az = 11.3f, alt = 89.3f, ha, dec;
+    float phpa = 800.f, tc = 10.f, rh = 0.7f;
+    volatile float newha, newdec, newalt;
+    timer_start();
+    for(int i = 0; i < N_TESTS; ++i){
+        // 260us per cycle for math.h sin/cos
+        // 34us per cycle for CORDIC sin/cos
+        altaz_to_hadec(alt, az, &ha, &dec);
+        hadec_to_altaz(ha, dec, &alt, &az);
+        newalt = alt + refraction(phpa, tc, rh, 90.f-alt);
+        altaz_to_hadec(newalt, az, (float*)&newha, (float*)&newdec);
+        (void) newha;
+        (void) newdec;
+        if((az += 9.51f) > 359.99f) az -= 359.9f;
+        if((alt -= 1.76f) < 9.9f) alt += 79.f;
+    }
+    timer_stop();
+    return timer_read();
+}
+
+// test LST calculation
+uint32_t test_astro_LST(){
+    uint32_t *uarr = (uint32_t*) arr;
+    volatile float result;
+    for(int i = 0; i < N_TESTS; ++i){ // fill random data in 21th century
+        uarr[i] = next_rand() % 3155673599 + 978307200;
+    }
+    timer_start();
+    for(int i = 0; i < N_TESTS; ++i){ // 1.5us per cycle
+        result = LST_from_unix(uarr[i]);
+        (void) result;
+    }
+    timer_stop();
+    return timer_read();
+}

G4:G431/CORDIC/test.h

@@ -34,3 +34,8 @@ uint32_t test_cordic_cos();
 uint32_t test_cordic_atan();
 uint32_t test_cordic_sqrt();
 uint32_t test_cordic_log();
+
+// Astronomy tests
+uint32_t test_astro_coordsTransform();
+uint32_t test_astro_refraction();
+uint32_t test_astro_LST();

G4:G431/CORDIC/version.inc

@@ -1,2 +1,2 @@
-#define BUILD_NUMBER "57"
+#define BUILD_NUMBER "75"
-#define BUILD_DATE "2026-09-05"
+#define BUILD_DATE "2026-09-08"