QUERY · ISSUE

Move esp32 REPL to a different UART

openby lerouxbopened 2019-12-09updated 2021-06-20

Hi.

I'm trying to change the ESP32 REPL to use UART2 rather than UART0. I'm using an Adafruit Feather Huzzah32 and I want to be able to use the REPL over the feather's RX/16 and TX/17 pins rather than the USB port. I believe this is UART2.

I've tried the following:

diff --git a/ports/esp32/mphalport.c b/ports/esp32/mphalport.c
index 305e87593..7edb40321 100644
--- a/ports/esp32/mphalport.c
+++ b/ports/esp32/mphalport.c
@@ -38,6 +38,8 @@
 #include "rom/uart.h"
 #endif

+#include "driver/uart.h"
+
 #include "py/obj.h"
 #include "py/stream.h"
 #include "py/mpstate.h"
@@ -80,6 +82,7 @@ void mp_hal_stdout_tx_strn(const char *str, uint32_t len) {
     if (release_gil) {
         MP_THREAD_GIL_EXIT();
     }
+    uart_tx_switch(UART_NUM_2);
     for (uint32_t i = 0; i < len; ++i) {
         uart_tx_one_char(str[i]);
     }
diff --git a/ports/esp32/uart.c b/ports/esp32/uart.c
index 10a4ba462..1de31dc0c 100644
--- a/ports/esp32/uart.c
+++ b/ports/esp32/uart.c
@@ -37,13 +37,13 @@ STATIC void uart_irq_handler(void *arg);

 void uart_init(void) {
     uart_isr_handle_t handle;
-    uart_isr_register(UART_NUM_0, uart_irq_handler, NULL, ESP_INTR_FLAG_LOWMED | ESP_INTR_FLAG_IRAM, &handle);
-    uart_enable_rx_intr(UART_NUM_0);
+    uart_isr_register(UART_NUM_2, uart_irq_handler, NULL, ESP_INTR_FLAG_LOWMED | ESP_INTR_FLAG_IRAM, &handle);
+    uart_enable_rx_intr(UART_NUM_2);
 }

 // all code executed in ISR must be in IRAM, and any const data must be in DRAM
 STATIC void IRAM_ATTR uart_irq_handler(void *arg) {
-    volatile uart_dev_t *uart = &UART0;
+    volatile uart_dev_t *uart = &UART2;
     uart->int_clr.rxfifo_full = 1;
     uart->int_clr.frm_err = 1;
     uart->int_clr.rxfifo_tout = 1;

But this doesn't seem to be enough. I've searched all over this codebase and cannot figure out how this fits together. Is there something obvious I'm missing?

CANDIDATE · PULL REQUEST

esp8266: Allow disable of REPL on UART0

closedby dmkentopened 2017-08-16updated 2018-05-21

This PR builds on the great initial work of @mhoffma in #2891. It rebases that work then extends those changes to address comments on #2891 by @dpgeorge, provide ability to enable/disable REPL and further decouple esp_mphal.c, machine_uart.c and uart.c from one-another

It pumps all UART RX into it's own ring buffer as well as conditionally to the main REPL input_buf. TX will go out on the UART as normal but this adds a conditional TX API for esp_mphal to use that will conditionally disable REPL TX to UART.

The conditional RX/TX behaviour is currently switched using an extra parameter to UART.init(). This would need to change to align with whatever is eventually decided in #3144. This shouldn't be very onerous if the uos.dupterm(obj, index) approach is adopted.

To make use of this behaviour the process is basically:

Boot ESP8266, connect via UART, use REPL on UART to setup webrepl.
Power down, connect whatever other device you want to your UART.
Boot and connect to webrepl.
Reinitalise the UART to disable REPL (and set other params as needed):

uart0.init(use_repl=0, baudrate=9600, rxbuflen=256)
Use the webrepl and the Pythonic UART API to talk to your other device using UART without any weird REPL interaction!

Move esp32 REPL to a different UART

esp8266: Allow disable of REPL on UART0

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