Hi,
Peter Stuge wrote:
> Peter Stuge wrote:
> > I suggest:
> >
> > 1. Move forward with SAMD11 replacing FTDI
> > 2. Add CTS+RTS to the UART interface
>
> I discovered that CTS+RTS are actually already connected to the USER FTDI
> in the rev03 schematic, but not to the MGMT FTDI. So at least some of the
> routing already exists!
>
> Paul, do you know if the STM32 USER UART init code enables nCTS+nRTS use?
I thought that the answer is yes, since:
commit 3109973fe239e60f4ec223ce95ef1609ea329e7c
Author: Fredrik Thulin <fred...@thulin.net>
Date: Wed May 18 14:44:01 2016 +0200
A little more robust file transfer
...
diff --git a/stm-init.c b/stm-init.c
index ab1905b..4421b21 100644
@@ -122,7 +122,7 @@ static void MX_USART2_UART_Init(void)
huart_user.Init.StopBits = UART_STOPBITS_1;
huart_user.Init.Parity = UART_PARITY_NONE;
huart_user.Init.Mode = UART_MODE_TX_RX;
- huart_user.Init.HwFlowCtl = UART_HWCONTROL_NONE;
+ huart_user.Init.HwFlowCtl = UART_HWCONTROL_RTS_CTS;
huart_user.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart_user) != HAL_OK) {
...but the answer is really no, hardware flow control has never worked
on the Alpha. If anyone has experienced communication issues then this
might well be why. A patch is attached.
> In a couple of days I'll check if wiring them to my SAMD11 daughterboard2
> does anything.
I've done this now. It turned out to be complicated, so it took a while.
The daughterboard2 I use for SAMD11 firmware testing and development covered
most of the FTDI chip so I soldered wires to the STM32 pins, which was fiddly,
and then I had to desolder the FTDI chip, because it seems to drive RTS even
when held in reset! >:( Then I observed that STM32 ignored CTS, guessed that
initialization was incorrect, and learned the horrible HAL way to fix that.
The good news is that a SAMD11 firmware using hardware flow control and
interrupts, no DMA, sends RPC_GET_VERSION to STM32 and receives the
response correctly every time, once the STM32 init code has been fixed.
So the SAMD11 USB interface I propose has been tested, and is reliable.
Kind regards
//Peter
From e102894d7084e9a839ff8f2a889f8fe21d46f625 Mon Sep 17 00:00:00 2001
From: Peter Stuge <pe...@stuge.se>
Date: Sat, 6 Jun 2020 04:00:31 +0200
Subject: [PATCH] stm-uart.c: Program CTS and RTS pins as alternate functions
---
stm-uart.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/stm-uart.c b/stm-uart.c
index f64c90c..9a5e53a 100644
--- a/stm-uart.c
+++ b/stm-uart.c
@@ -69,6 +69,20 @@ static void MX_DMA_Init(void)
/* USART1 init function */
static void MX_USART1_UART_Init(void)
{
+ GPIO_InitTypeDef g;
+ g.Mode = GPIO_MODE_AF_PP;
+ g.Pull = GPIO_NOPULL;
+ g.Speed = GPIO_SPEED_LOW;
+ g.Alternate = GPIO_AF7_USART1;
+
+ /* USART1_CTS */
+ g.Pin = GPIO_PIN_11;
+ HAL_GPIO_Init(GPIOA, &g);
+
+ /* USART1_RTS */
+ g.Pin = GPIO_PIN_12;
+ HAL_GPIO_Init(GPIOA, &g);
+
huart_mgmt.Instance = USART1;
huart_mgmt.Init.BaudRate = USART_MGMT_BAUD_RATE;
huart_mgmt.Init.WordLength = UART_WORDLENGTH_8B;
@@ -90,6 +104,20 @@ static void MX_USART1_UART_Init(void)
/* USART2 init function */
static void MX_USART2_UART_Init(void)
{
+ GPIO_InitTypeDef g;
+ g.Mode = GPIO_MODE_AF_PP;
+ g.Pull = GPIO_NOPULL;
+ g.Speed = GPIO_SPEED_LOW;
+ g.Alternate = GPIO_AF7_USART2;
+
+ /* USART2_CTS */
+ g.Pin = GPIO_PIN_0;
+ HAL_GPIO_Init(GPIOA, &g);
+
+ /* USART2_RTS */
+ g.Pin = GPIO_PIN_1;
+ HAL_GPIO_Init(GPIOA, &g);
+
huart_user.Instance = USART2;
huart_user.Init.BaudRate = USART_USER_BAUD_RATE;
huart_user.Init.WordLength = UART_WORDLENGTH_8B;
--
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