Fix UART passthrough in firmware 3.x

Author: bessman

pslab/bus/uart.py

@@ -170,7 +170,9 @@ def _write_byte(self, data: int):
         self._device.send_byte(CP.UART_2)
         self._device.send_byte(CP.SEND_BYTE)
         self._device.send_byte(data)
-        self._device.get_ack()
+
+        if self._device.firmware.major < 3:
+            self._device.get_ack()
 
     def _write_int(self, data: int):
         """Write a single int to the UART bus.

pslab/protocol.py

@@ -1,5 +1,6 @@
 """TODO"""
 
+import enum
 import struct
 
 
@@ -179,16 +180,16 @@
 FILL_BUFFER = Byte.pack(27)
 
 # /*---------- BAUDRATE for main comm channel----*/
-SETBAUD = Byte.pack(12)
-BAUD9600 = Byte.pack(1)
-BAUD14400 = Byte.pack(2)
-BAUD19200 = Byte.pack(3)
-BAUD28800 = Byte.pack(4)
-BAUD38400 = Byte.pack(5)
-BAUD57600 = Byte.pack(6)
-BAUD115200 = Byte.pack(7)
-BAUD230400 = Byte.pack(8)
-BAUD1000000 = Byte.pack(9)
+SETBAUD_LEGACY = Byte.pack(12)
+BAUD9600_LEGACY = Byte.pack(1)
+BAUD14400_LEGACY = Byte.pack(2)
+BAUD19200_LEGACY = Byte.pack(3)
+BAUD28800_LEGACY = Byte.pack(4)
+BAUD38400_LEGACY = Byte.pack(5)
+BAUD57600_LEGACY = Byte.pack(6)
+BAUD115200_LEGACY = Byte.pack(7)
+BAUD230400_LEGACY = Byte.pack(8)
+BAUD1000000_LEGACY = Byte.pack(9)
 
 # /*-----------NRFL01 radio module----------*/
 NRFL01 = Byte.pack(13)
@@ -229,7 +230,8 @@
 # --------COMMUNICATION PASSTHROUGHS--------
 # Data sent to the device is directly routed to output ports such as (SCL, SDA for UART)
 
-PASSTHROUGHS = Byte.pack(15)
+PASSTHROUGHS = Byte.pack(12)
+PASSTHROUGHS_LEGACY = Byte.pack(15)
 PASS_UART = Byte.pack(1)
 
 # /*--------STOP STREAMING------*/

pslab/sciencelab.py

@@ -282,30 +282,38 @@ def _write_data_address(self, address: int, value: int):
         self.send_int(value)
         self.get_ack()
 
-    def enable_uart_passthrough(self, baudrate: int, persist=False):
+    def enable_uart_passthrough(self, baudrate: int):
         """Relay all data received by the device to TXD/RXD.
 
-        If a period > 0.5 seconds elapses between two transmit/receive events,
-        the device resets and resumes normal mode. This timeout feature has
-        been implemented in lieu of a hard reset option.
-
         Can be used to load programs into secondary microcontrollers with
         bootloaders such ATMEGA or ESP8266
 
         Parameters
         ----------
         baudrate : int
-            Baudrate of the UART bus.
-        persist : bool, optional
-            If set to True, the device will stay in passthrough mode until the
-            next power cycle. Otherwise(default scenario), the device will
-            return to normal operation if no data is sent/received for a period
-            greater than one second at a time.
+            Baudrate of the UART2 bus.
         """
+        if self.firmware.major < 3:
+            self._uart_passthrough_legacy(baudrate)
+        else:
+            self._uart_passthrough(baudrate)
+
+    def _uart_passthrough(self, baudrate: int) -> None:
         self.send_byte(CP.PASSTHROUGHS)
         self.send_byte(CP.PASS_UART)
-        self.send_byte(1 if persist else 0)
-        self.send_int(int(round(((64e6 / baudrate) / 4) - 1)))
+        self.send_int(self._get_brgval(baudrate))
+        self.interface.baudrate = baudrate
+
+    def _uart_passthrough_legacy(self, baudrate: int) -> None:
+        self.send_byte(CP.PASSTHROUGHS_LEGACY)
+        self.send_byte(CP.PASS_UART)
+        disable_watchdog = 1
+        self.send_byte(disable_watchdog)
+        self.send_int(self._get_brgval(baudrate))
+
+    @staticmethod
+    def _get_brgval(baudrate: int) -> int:
+        return int((CP.CLOCK_RATE / (4 * baudrate)) - 1)
 
     def read_log(self):
         """Read hardware debug log.