From c4c3429bf6a53e4c78f1d47e3b18df8b33e59745 Mon Sep 17 00:00:00 2001
From: Benjamin Koch <bbbsnowball@gmail.com>
Date: Wed, 24 May 2023 01:18:38 +0200
Subject: [PATCH] some small changes
---
firmware/rust1/src/rs485.rs | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/firmware/rust1/src/rs485.rs b/firmware/rust1/src/rs485.rs
index 314a006..38915c8 100644
--- a/firmware/rust1/src/rs485.rs
+++ b/firmware/rust1/src/rs485.rs
@@ -248,7 +248,7 @@ impl RS485 {
// We have a long 1, i.e. UART is idle. Wait for start bit.
"have_long_high:",
- "irq set 1", // notify MCU in case they want to know about this (start of Modbus frame)
+ "irq set 1", // notify MCU in case they want to know about this (end of Modbus frame)
"wait 0 pin 0",
"nop [4]",
"jmp pin wait_idle", // abort if zero was just a glitch
@@ -324,8 +324,8 @@ impl RS485 {
let mut cfg = Config::default();
let loaded_program = common.load_program(&relocated);
cfg.use_program(&loaded_program, &[]);
- const SM_FREQ: u32 = 125_000_000;
- cfg.clock_divider = (U56F8!(125_000_000) / U56F8!(125_000_000 /* SM_FREQ */)).to_fixed();
+ const SM_FREQ: u32 = 25_000_000;
+ cfg.clock_divider = (U56F8!(125_000_000) / U56F8!(25_000_000 /* SM_FREQ */)).to_fixed();
cfg.shift_in = ShiftConfig {
auto_fill: true,
threshold: 32,
@@ -343,9 +343,10 @@ impl RS485 {
sm.set_config(&cfg);
sm.set_enable(true);
- // Timeout: Modbus wants 1.5 ms between frames so we make this a bit smaller. SM runs at 25 MHz
- // but we need two clocks per loop.
- let timeout_start_value = (SM_FREQ as f32 * 1.4e-3 / 2.) as u32;
+ // Timeout: Modbus wants 3.5 char times between frames but we should detect the end of a frame
+ // after 1.5 char times. This is 0.86 ms at 19200 baud (8e1, i.e. 11 baud times per char).
+ // We need two clocks for each loop.
+ let timeout_start_value = (SM_FREQ as f32 * 0.86e-3 / 2.) as u32;
sm.tx().push(timeout_start_value);
info!("timeout_start_value: {} = 0x{:08x}", timeout_start_value, timeout_start_value);
@@ -395,7 +396,6 @@ impl RS485 {
let mut rxcrc = CRC.digest();
let mut rx_expected_bytes = ModbusFrameLength::NeedMoreData(3);
let mut rx_received_bytes = 0u16;
- let mut rx_char_prev: u8 = 0;
const TX_BUF_LENGTH: usize = 32;
let mut txbuf = Vec::<u8, TX_BUF_LENGTH>::new();
@@ -560,19 +560,19 @@ impl RS485 {
tx_data[i + 1] = x as u32 | (((parity as u32) & 1) << 8);
}
+ info!("Modbus reply: {:?}", txbuf);
+
tx_future = DontAbort::new(sm1.tx().dma_push(dma_tx_ref.reborrow(),
&tx_data[0..(txbuf.len()+1)]), HangIfReused);
}
}
rxbuf.clear();
- rxcrc = CRC.digest();
+ //rxcrc = CRC.digest(); // re-init already done above, don't repeat to avoid warning
rx_expected_bytes = ModbusFrameLength::NeedMoreData(3);
rx_received_bytes = 0;
}
}
-
- rx_char_prev = rx_char;
},
Result::Err(e) => {
info!("RX error {:?}", e);
--
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