New firmware release 1.4.0.b1

[mohpor]

@crankshaft

The amount of available ram is just too small to do anything that includes anything more than one or 2 libraries, I managed to get the fantastic bosch BMP280 enviro sensor working, and cobbled together a mqtt client, however they cannot work together due to insufficient ram, and so I have to now find an alternative sensor that is easier to decode.

I was facing memory issues but I got to solve them. The key is gc.collect()! You can't over use it! I mean, I have gc.collect() all over the place! I'm not sure about it's implications on battery usage and performance, but that is the only way I can run my code now! Every loop iteration, every major memory altering event (especially around threads and interrupts). I have learnt it the hard way, it might help you with your application too.

A good pattern to use is try-finally in interrupt handlers and memory consuming functions:

try:
    # Do some memory consuming function
    for x in list:
       #do things
       gc.collect()
    wlan.deinit()
    gc.collect()
    ble.deinit()
    gc.collect()
finally:
    gc.collect() 

Hope it helps somebody.

Cheers,
M.

[robrush]

Hi folks,

• Still nothing about machine.sleep() or machine.deepsleep()?
• I also tried to measure the current i used by my LoPy with machine.idle() or not... I couldn't find any difference. Does someone have an idea of the current used by the CPU at 100% or close to 0%. The difference is probably too small to be seen.

[crankshaft]

@daniel - Thanks, and joining forces with Damien George sounds like a great move too :-)

[crankshaft]

@mohpor, @jmarcelino, @livius - Thanks for the suggestions regarding MQTT and BME280 and memory etc.

Compared to the Si7021 AND SHT21, the BME requires a lot more code in the driver library to extract the data, probably 3 times as much as for the S* devices, which are really simple and is what I am using now.

Other than getting data about the environment, I need to get data from other sensors, and really need to provide a simple HTTP server so that the device can initially be configured (an maintained) from a web browser and a few other things too.

My code needs to be very robust as once it is deployed (on the other side of the world) it needs to look after itself, and manage any and all errors, and with the limited code space right now I simply cannot do this.

I know that if I strip down to bare functionality, I could get the basics to work, but that's not what I am after, I need much more than I have now in order for this project to succeed.

If I were to use a 8266 device (nodeMCU or micropython) then I believe I can get it all in, and my expectations were that I would be able to do more on the ESP32 rather than less.

I don't really require any help with the programming side of things right now, just need more space to breathe :-)

[livius]

@crankshaft
you can compile py file it use then much less memory
but still this require custom firmware build with enabled option for compiled modules

look here:
https://forum.pycom.io/topic/486/v-1-8-7-micropython-released-support-importing-compiled-mpy-files-more-ram/2
and here - detile how to do this:
https://forum.pycom.io/topic/453/memoryerror-memory-allocation-failed-allocating-2048-bytes-lopy-1-2-0-b1/2

[tholden]

machine.idle is not working.

I am executing it as the first thing in the code, but it still continues execution

[robrush]

@tholden agree with you. See my comment below

[mohpor]

@sakis

Now I can see why everybody submit their issues here.

I have opened an issue on Github's repo, no one even acknowledges my issue there. People get way more attention from posting here.

[Colateral]

@livius Have you succeed to get data from BMP180 . I am always get "I2C bus error" when I am trying to instantiate bmp180.
Debuging, I2C bus scan displays 119 address available, but when I simply read the bmp180 chip id, with i2c.readfrom_mem(119, 0xD0, 2) I am getting "I2C bus error".

This is happening always on LoPy.

[livius]

@Colateral
yes i can read data from it but fix is not clear to me - i still can not diagnose what is crux of the problem.

I can not work with BMP180 alone i must have something more on bus like e.g. light sensor BH1750
if i reverse sensors initialization order i got always I2C bus error
it looks like i must write something one to i2c and then i can read from it or vice versa.
It is not connected with the resistance or the capacitance.

I do not know if i2c is now hardware or still software implementation

[jmarcelino]

@livius said in New firmware release 1.4.0.b1:

I do not know if i2c is now hardware or still software implementation

i2c is still done in software.

Is anyone using external pull-up resistors on their I2C? I see the internal ESP32 pull-ups are enabled in the code, but have not seen any reference to what the resistance value is like or attempted to measure it.

[livius]

@jmarcelino said in New firmware release 1.4.0.b1:

I tested with and without resistors but "nothing" change
only reverse order of initialization of sensors help

difference between sensors is that in light sensor first is memwrite
in bm180 first is memread

and problem appear in 1.4 version of firmware - previously all work without any problem
i do not dig what was changed on esp-idf in the mean time

[Colateral]

@livius Using the same board and connectivity, I can tell you that I succeed to read BME280 (alone) without any resistors or etc.

I have 2 BMP180 sensors from 2 different providers. BME280 and these 2 sensors, I can read them with Arduino ... but not at all with the PyCom I2C stack. This make me think that something is "nasty" with in the I2C implementation...

Which rate are did you configured your I2C baudrate in order to read BMP180?
Using your BMP180, If you run: print(i2c.readfrom_mem(119, 0xD0, 2)) ... can you got the chip id?

[livius]

@Colateral
bus = I2C(0, I2C.MASTER, baudrate=100000, pins=("P19", "P20"))

return:
b'U\x02'

print(ubinascii.hexlify(bus.readfrom_mem(119, 0xD0, 1))) 
b'55'
print(ubinascii.hexlify(bus.readfrom_mem(119, 0xD0, 2))) 
b'5502'

and chip revision:

>>> print(ubinascii.hexlify(bus.readfrom_mem(119,0xd1, 2))) 
b'0206'

it looks ok 550206