rshell & Raspberry Pi Pico - date & time sync

[DWiskow]

A user on the Raspberry Pi forum posted this https://www.raspberrypi.org/forums/view ... 6#p1810426, which appears to set the Pico RTC from within MicroPython.

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import machine
import utime
print()
print("                           YYYY MM DD HH MM SS")
dateTime = (input ("Enter current date & time: "))+' 0 0'
givenTime = utime.mktime(list(map(int, tuple(dateTime.split(' ')))))

ctime=utime.localtime(givenTime)

# ok insert data into the rtc

setup_0 = (ctime[0] << 12) | (ctime[1] << 8) | ctime[2]

def weekDay(year, month, day):
    offset = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334]
    afterFeb = 1
    if month > 2: afterFeb = 0
    aux = year - 1700 - afterFeb
    # dayOfWeek for 1700/1/1 = 5, Friday
    dayOfWeek  = 5
    # partial sum of days betweem current date and 1700/1/1
    dayOfWeek += (aux + afterFeb) * 365                  
    # leap year correction    
    dayOfWeek += aux // 4 - aux // 100 + (aux + 100) // 400     
    # sum monthly and day offsets
    dayOfWeek += offset[month - 1] + (day - 1)               
    dayOfWeek %= 7
    return int(dayOfWeek)

setup_1 =  (ctime[3] << 16) | (ctime[4] << 8) | ctime[5]
setup_1 =  setup_1 |  (weekDay(ctime[0],ctime[1],ctime[2]) << 24)
# Be aware that RTC start at sunday=0
# and utime start dayofweek monday=0

# set rtc
machine.mem32[0x4005c004]= setup_0
machine.mem32[0x4005c008]= setup_1
machine.mem8[0x4005c00c] = machine.mem8[0x4005c00c] | 0x10

Could this be of help in getting rshell to synchronise date & time on connection ?

[DWiskow]

more detail and a working example of how to synchronise the Raspberry Pi Pico to a host computer . . . can this now be incorporated into rshell?

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#!/usr/bin/env python3
#
# Vendor:Product ID for Raspberry Pi Pico is 2E8A:0005
#
# see section 4.8 RTC of https://datasheets.raspberrypi.org/rp2040/rp2040-datasheet.pdf and in particular section 4.8.6 
# for the RTC_BASE address (0x4005C000) and details of the RD2040 setup registers used to program the RTC
#
from serial.tools import list_ports
import serial, time

picoPorts = list(list_ports.grep("2E8A:0005"))

utcTime = str( int(time.time()) )
pythonInject = [
    'import machine\r\n',
    'import utime\r\n',
    'rtc_base_mem = 0x4005c000\r\n',
    'atomic_bitmask_set = 0x2000\r\n',
    'led_onboard = machine.Pin(25, machine.Pin.OUT)\r\n',
    '(year,month,day,hour,minute,second,wday,yday)=utime.localtime('+utcTime+')'+'\r\n',
    'machine.mem32[rtc_base_mem + 4] = (year << 12) | (month  << 8) | day\r\n',
    'machine.mem32[rtc_base_mem + 8] = ((hour << 16) | (minute << 8) | second) | (((wday + 1) % 7) << 24)\r\n',
    'machine.mem32[rtc_base_mem + atomic_bitmask_set + 0xc] = 0x10\r\n',
    'for i in range(5):\r\n',
    '    led_onboard.toggle()\r\n',
    '    utime.sleep(0.03)\r\n',
    'led_onboard.value(0)\r\n'
    ]

if not picoPorts:
    print("No Raspberry Pi Pico found")
else:
    picoSerialPort = picoPorts[0].device
    with serial.Serial(picoSerialPort) as s:
        s.write(b'\x03')
        s.write(b'\x03')
        s.write(b'\x01')       
        for n in range(len(pythonInject)):
            s.write(bytes(pythonInject[n], 'ascii'))
        time.sleep(0.1) 
        s.write(b'\x04')
        s.write(b'\x02')
    print( 'Raspberry Pi Pico found at '+str(picoSerialPort)+'\r' )
    print( 'Host computer epoch synchronised over USB serial: '+utcTime+'\r' )

The above code is designed to be executed on a host computer (Windows, Mac or Linux) and will automagically find your connected Pico and then synchronise its date and time (this code requires that python3 and pyserial are installed on the host computer).

No MicroPython code needs be added or running on the Pico for this to work, but Thonny does need to closed (so as not to block the USB serial port) whilst it does it's magic

It works by injecting a small MicroPython script, which it modifies on the fly with the host computers UTC, into the Pico over the USB serial link using the RAW REPL functionality of MicroPython (kudos to rshell for some of the ideas/techniques used https://github.com/dhylands/rshell)

Oh, and the injected code generates a short pulse of the Pico on-board LED to let the user know the RTC has been synchronised

More information can be found on pyserial here https://pyserial.readthedocs.io/en/latest/pyserial.html. To install pyserial enter the following on the host computer command line.

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python -m pip install pyserial

NOTE: if code is running on the Pico, the synchronisation process will interrupt it. You can restart the code running on your Pico board using Thonny, provided you don't disconnect it from power (effectively reseting it). If you do reset the Pico, or disconnect it from power, you will need to re-sync your Pico board with a host computer again to have an accurate RTC (by default, at startup, the MicroPython interpreter running on the Pico initialises the Pico system clock to 1609459201 - Thursday, 1st January 2021 00:00:01)

This post https://www.raspberrypi.org/forums/view ... 6&t=300676 provides some more information regarding how to achieve a ‘RTC battery backup’ by attaching a battery to VSYS and GND, but it does have the disadvantage of powering the whole Pico (~ 19mA) rather than just the RTC.

[dhylands]

rshell already tries to synchronize the time on the connected device when you launch rshell.

I see that the Pico doesn't work. I'll take a look and see if I can incorporate this.

[dhylands]

The rshell pico branch: https://github.com/dhylands/rshell/tree/pico now sets the RTC on the Pico properly.

You can use rshell's date command to get the date on the host and add the -b BOARDNAME (use a BOARDNAME of pyboard by default).

So you should now see something like this:

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/Users/davehylands/micropython/rshell> date; date -b pyboard
Host: Tue Feb  2 15:59:20 2021
pyboard: Tue Feb  2 15:59:20 2021

[DWiskow]

Fantastic, thanks

minor tweak, I think line 1008 should use ‘mem32’ rather than ‘mem8’ as it is a 32bit register [this was an error in the original code I supplied, but it seemed to work irrespective]

[JumpZero]

Excellent! Thank you

[dhylands]

Fantastic, thanks

minor tweak, I think line 1008 should use ‘mem32’ rather than ‘mem8’ as it is a 32bit register [this was an error in the original code I supplied, but it seemed to work irrespective]

Yes - it turns out on the the pico that all registers should be accessed as 32-bits. I found this in the datasheet (2.1.4. Narrow IO Register Writes):

Memory-mapped IO registers on RP2040 ignore the width of bus read/write accesses. They treat all writes as though they
were 32 bits in size. This means software can not use byte or halfword writes to modify part of an IO register: any write to
an address where the 30 address MSBs match the register address will affect the contents of the entire register.

I've updated the rshell pico branch.

It turns out that the CTRL register is only 9 bits wide which makes the mem8 happen to work in this particular scenario. machine.mem8[addr] = 0x12 winds up being the same as machine.mem32[addr] = 0x12121212

[zyghom]

good day all good people
I am trying to solve the issue that might be solved already but let me ask nevertheless:
Pico working offline and doing some things - sending data from sensors and writing also to the logfile.
One of the columns should be date/time.
As I realised: Pico not connected anywhere starts after reset/power off from 1 Jan 2020. But I have connected DS1302 and it has proper time on it. Can I set the date/time on Pico using RTC date/time or should I simply get date/time from RTC?
Does utime.localtime() only provide date/time or also I can set it correctly?

I know that Thonny, once connected it will set proper time but my issue is: I don't want Tonny to be connected - Pico works offline and after power off/reset I would like still to have proper date/time without my manual intervention: connecting my laptop to Pico.

As I can see here and there: if rshell/Thonny can set the time on Pico, there must be a command somewhere to get the time from RTC (this I know obviously - it is a part of DS1302 library) and then set on Pico?

Thank you for some advice.

Btw I started with Picos and I love them. Also I would prefer to stay with Micropython rather than Circuitpython - somehow it works better for me

[Roberthh]

You can set the rp2 rtc with rtc.datetime(). Use:

from machine import RTC
rtc=RTC()
rtc.datetime((year, month, day, weekday, hour, minute, second, 0))

The two brackets are essential, and it has to be an 8 element tuple.

[zyghom]

You can set the rp2 rtc with rtc.datetime()...

I wish you live for ever
Thank you