From 35ce9db36a4b8f192a52e1c3fc44ab735b84c740 Mon Sep 17 00:00:00 2001
From: Edward Emelianov <edward.emelianoff@gmail.com>
Date: Sat, 7 Jan 2023 14:37:46 +0300
Subject: [PATCH] make more readable & accurate

---
 G0:G070/usart/usart.bin | Bin 1728 -> 1724 bytes
 G0:G070/usart/usart.c   |   4 +++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/G0:G070/usart/usart.bin b/G0:G070/usart/usart.bin
index cf20a4438c7ac6955af8f36bb5ef04edb9a10af0..a6b12499e71a9e93df7ed4a6234437413a58d8f1 100755
GIT binary patch
delta 395
zcmX@WyN6eRVFH7~QC0?ygFw6&h$jk4*E4`P3{U`KA7p??f`mYduwj^7EEai~95#KJ
zV%!J|9&X$k&&VJBQ-OiuL&Q%eMFkIr58oy$Gbu`M|Dm0EoBi@t2IU!Um!FFO#jSqc
zcrFa2%_he)SqiRTW8h$6U{Kfsq#J;^VDd_);`(l7DX-ZKmlGB!OS1+i98jL6I5|Pg
zTiio3LELj@LYJbLw`77CkmaBlnIP)PnbFC}DPgW~GeOvs1Be+dK%`&-qoSviU{be|
zR6>K2fcGR;5PgY3DxtugL4e8O|NjsF8F&~17(5spWEhwncz~|Z0J04jm^RO64rbyn
V`1|kq0XJZnD1aQeV=^P#egGq9V#fdg

delta 395
zcmdnPdw^GfVFH7~Nmd4qqd<HRh$jk4*E4`P3{U`;V1P)1gg}b0VVGPZ7I~N)Hhq|4
z+z1PvZrmEr$RGPtfq~&e)K4Zw1rLS~KPD?PDN67Bp`Ce~{qj`?<r!|5pNjy+ZGPT(
zE)1kCCdV^b3a(*e;9y~3P}l*aTY$J^@=B)SdMPhy?^%kM6BZ~-vj!&|P@bG1;Vt1I
znIPdgGoedS!W+VJP>f6v_vFmzWaN}ESGbuV>d67bj20XTBA$W?jEbI4f=S&<QV9)8
zg5Hx@LG&dCse}Ue18xigOb-A5fB4V9!w|sW!Qi0H#K0iKz~sOKbcu!s!{+JC;Y|E_
TfB!uPDg_FG9JpulU)KEqwM%45

diff --git a/G0:G070/usart/usart.c b/G0:G070/usart/usart.c
index 30da0bd..bd22c4b 100644
--- a/G0:G070/usart/usart.c
+++ b/G0:G070/usart/usart.c
@@ -39,6 +39,8 @@ char *usart3_getline(int *wasbo){
     return rbuf[!rbufno]; // current buffer is in filling stage, return old - filled - buffer
 }
 
+#define USART_BRR(speed)    ((64000000 + speed/2) / speed)
+
 // USART3 @ PD8 (Tx) and PD9 (Rx) - both AF0
 void usart3_setup(){
     RCC->IOPENR |= RCC_IOPENR_GPIODEN; // enable PD
@@ -51,7 +53,7 @@ void usart3_setup(){
     // enable USART3 clocking
     RCC->APBENR1 |= RCC_APBENR1_USART3EN;
     // baudrate 115200
-    USART3->BRR = 640000 / 1152;
+    USART3->BRR = USART_BRR(115200);
     // eol character: '/n'
     USART3->CR2 = USART_CR2_ADD_VAL('\n');
     // enable DMA transmission