SPI.write_readinto not working anymore after firmwareupdate

[Tom]

I updated the firmware from version 1.10.2.b1 to ver. 1.15.0.b1. after the update the command spi.write_readinto returned only zeros. I checked MISO, MOSI, CLK and CS lines everything as expected.
I then went back in firmware to ver. 1.10.2.b1 as described in: https://forum.pycom.io/topic/517/downgrading-firmware-advanced-users
With old firmware the same code is running again.
Is there a command that changed with firmwareupdate?

[seb]

Hi,

I just tested this function on version 1.15.0.b1 and it worked successfully. This code has not been changed so maybe the issue lies elsewhere. Could you please share your source code?

[Tom]

Here is my code. It is written for the barometer MS5611.
[1_1518533565589_main.py](Lade 100% hoch) [0_1518533565589_boot.py](Lade 100% hoch) [0_1518533588418_MS5611.py](Lade 100% hoch)

[seb]

Those files haven't been properly uploaded by the looks of it. In your code to do specify the exact pins that the SPI should use or are you replying on the defaults? The defaults changed recently because on newer modules P12 controls which WiFi antenna is used. If you don't specify the pins, add this and let me know if this fixes it.

[Tom]

main.py

import machine
import os
from machine import UART
from machine import Pin
from machine import SPI

#MS5611_CS = Pin('P3', mode= Pin.OUT) #Pulling CS-Pin LOW activates the device
LIS331_CS = Pin('P2', mode= Pin.OUT)
MCP_00_CS = Pin('P22', mode= Pin.OUT)
MCP_01_CS = Pin('P21', mode= Pin.OUT)
#Pulling CS-Pin LOW activates the device

#MS5611_CS.value(1)- is defined in the class
LIS331_CS.value(1)
MCP_00_CS.value(1)
MCP_01_CS.value(1)

spi = SPI(0, mode = SPI.MASTER, baudrate=2000000, polarity=0, bits=32, phase=0)

baro = MS5611()
baro.reset()

while True:

A= baro.get_altitude_temp()
print(A)
time.sleep(1)

library
from machine import SPI
from machine import Pin
import time

class MS5611:

CMD_MS5611_RESET = const(0x1E)
CMD_MS5611_PROM_Setup = const(0xA0)
CMD_MS5611_PROM_C1 = const(0xA2)
CMD_MS5611_PROM_C2 = const(0xA4)
CMD_MS5611_PROM_C3 = const(0xA6)
CMD_MS5611_PROM_C4 = const(0xA8)
CMD_MS5611_PROM_C5 = const(0xAA)
CMD_MS5611_PROM_C6 = const(0xAC)
CMD_MS5611_PROM_CRC = const(0xAE)
CMD_CONVERT_D1_OSR4096 = const(0x48)   # Maximum resolution (oversampling)
CMD_CONVERT_D2_OSR4096 = const(0x58)   # Maximum resolution (oversampling)

def __init__(self, CS_Pin='P3'):
    #spi = SPI(0, mode = SPI.MASTER, baudrate=2000000, polarity=0, bits=32, phase=0)
    self.CS = Pin(CS_Pin, mode= Pin.OUT)  #Pulling CS-Pin LOW activates the device

def reset(self):
    self.CS.value(0)
    time.sleep(1)
    spi.write(bytes([CMD_MS5611_RESET]))
    self.CS.value(1)
    time.sleep(2)
    self.calib = self._get_calibration()

def _read_calib_16(self,reg):
    buf3 = bytearray(3)
    self.CS.value(0)
    spi.write_readinto(bytes([reg,0x00,0x00]),buf3)
    self.CS.value(1)
    data = buf3[1]*256+buf3[2]
    return data

def _read_raw_32(self,reg):
    buf4 = bytearray(4)
    self.CS.value(0)
    spi.write(bytes([reg]))
    self.CS.value(1)
    time.sleep_ms(10) #needs to be at least 8.22ms
    self.CS.value(0)
    spi.write_readinto(bytes([0x00,0x00,0x00,0x00]),buf4)
    self.CS.value(1)
    val = 65536*buf4[1]+256*buf4[2]+buf4[1]
    return val

def _get_calibration(self): #is called in reset stored as self.calib
    C1 = self._read_calib_16(CMD_MS5611_PROM_C1)
    C2 = self._read_calib_16(CMD_MS5611_PROM_C2)
    C3 = self._read_calib_16(CMD_MS5611_PROM_C3)
    C4 = self._read_calib_16(CMD_MS5611_PROM_C4)
    C5 = self._read_calib_16(CMD_MS5611_PROM_C5)
    C6 = self._read_calib_16(CMD_MS5611_PROM_C6)
    return C1,C2,C3,C4,C5,C6

def _get_temperature_raw(self):
    T_raw = self._read_raw_32(CMD_CONVERT_D2_OSR4096)
    return T_raw

def _get_pressure_raw(self):
    p_raw = self._read_raw_32(CMD_CONVERT_D1_OSR4096)
    return p_raw

def _calc_calibration_values(self):
    T_raw = self._get_temperature_raw()
    dT = T_raw-self.calib[4]*256
    OFF = self.calib[1]*65536+(self.calib[3]*dT)/128
    SENS = self.calib[0]*32768+(self.calib[2]*dT)/256
    return dT, OFF, SENS

def get_temp_press(self):
    [dT,OFF,SENS]=self._calc_calibration_values()
    p_raw =self._get_pressure_raw()
    TEMP = 2000+dT*self.calib[5]/8388608
    PRESS = (p_raw*SENS/2097152-OFF)/32768
    return TEMP/100, PRESS

def get_altitude_temp(self): #calculation Altitude using standart 1013.25 mbar at sea level reference
    [TEMP,PRESS] =self.get_temp_press()
    tmp = (PRESS/101325.0)
    tmp = pow(tmp, 0.190295)
    Altitude = 44330.0 * (1.0-tmp)
    return Altitude, TEMP

[seb]

Can you try specifying the pin in your code like so:

spi = SPI(0, mode=SPI.MASTER, baudrate=2000000, polarity=0, phase=0, pins=('P10','P11','P14'))

We changed our default SPI pins recently and this might be what's causing the issue

[Tom]

I'am using L01 and it is soldered on a PCB I made myself. Therefore changing from Pin12 to Pin14 is not possible for me.

Instead I tested:

   spi = SPI(0, mode = SPI.MASTER, baudrate=2000000, polarity=0, phase=0, pins=('P10','P11','P12'))

It works again. But using Pin12 as MISO is not a good idea anyway since MISO in my case is held high by the slave. Pin12 is used to change the boot mode as well. If it's hold high long enough it selects factory firmware instead.
In my case this prevents the board from autostarting boot.py and main.py.

Is there a workaround?

[seb]

@tom

The safe boot functionality of pin 12 has always been like that, the only advice I can give to work around this issue is to modify the micropython firmware to use a different pin and build it from source. The change is quite trivial, you will just need to change this one line to a different GPIO number, https://github.com/pycom/pycom-micropython-sigfox/blob/ec4c3bb22a59a06870f37ea05d4be054c9bf44ef/esp32/boards/LOPY/mpconfigboard.h#L15

[PikWay]

@seb
Thanks!
Someone should fix this in doc. I'm running the latest stable firmware on wipy3, SPI device is hooked to default pins (as in pinout diagram) and it wasn't working until I've explicitly passed them in pins during SPI initialization.
Most of the day yesterday I was struggling to make it work.