Category: Embedded

circuit python 9.1 beta 3

whbeebe
CircuitPython web page with date and time added

No sooner did I write my post about CircuitPython 9.1 beta 2, then CircuitPython 9.1 beta 3 dropped with 24 hours of beta 2’s release. Apparently beta 2 introduced an “issue” (i.e. major bug) with the adafruit_esp32spi library. A bit of irony because I can’t get any CircuitPython builds to install on any of my Espressif ESP32-S3 boards, even though the CircuitPython site explicitly calls those boards out as being supported. Instead I’m using CircuitPython on every board except Espressif boards.

Rather than repeat the same code drop from yesterday, I added the ability to query the internet for time via NTP and the adafruit_ntp library. You can see the one line that sets up an ntp instance to query for time on the network at line 47 in the listing below, and the function format_ntp at line 57 does exactly that, creating a string with formatted time. The lead-in screen capture shows how the date and time are formatted, right beneath the displayed CircuitPython version. If you need accurate time in your project, and if you’re connected to the internet via WiFi with this device, then using the Adafruit NTP library is super easy to set up.

One other note: there’s a new property to define in your settings.toml file named TZ_OFFSET, or the timezone offset. That’s used to set up the ntp instance. I have mine set to -4 for eastern daylight time.

import osimport timeimport ipaddressimport wifiimport socketpoolimport boardimport microcontrollerimport adafruit_connection_managerimport adafruit_ntpfrom digitalio import DigitalInOut, Directionfrom adafruit_httpserver import Server, Request, Response, POST# On-device LED setupled = DigitalInOut(board.LED)led.direction = Direction.OUTPUTled.value = False# Connect to a local WiFi access point.# Because this code is running in a CircuitPython 9 or later environment,# it requires a settings.toml file be created with at least the following# six lines:## AP_SSID = "WIFI SSID"# AP_PASSWORD = "WIFI PASSWORD"# STATIC_IP = "IP4 dotted IP address"# GATEWAY = "192.168.0.1"# TZ_OFFSET = -4# DEBUG = "True" ## DEBUG can be either True or False.ipv4 =  ipaddress.IPv4Address(os.getenv('STATIC_IP'))netmask =  ipaddress.IPv4Address("255.255.255.0")gateway =  ipaddress.IPv4Address(os.getenv('GATEWAY'))wifi.radio.set_ipv4_address(ipv4=ipv4,netmask=netmask,gateway=gateway)wifi.radio.connect(os.getenv('AP_SSID'), os.getenv('AP_PASSWORD'))print(" Connected to WiFi access point...")pool = socketpool.SocketPool(wifi.radio)server = Server(pool, "/static", debug=os.getenv('DEBUG'))# Create Network Time Protocol (NTP) query instance. Use it to get the time.ntp = adafruit_ntp.NTP(pool, tz_offset = os.getenv('TZ_OFFSET'))# This is where the ntp instance created above is used. Get the time at the# instance the function is called, then format the raw data into a human# readable string.## The format is:# dayname, monthday monthname year - hour:min:sec# where the time is in 24 hour format.def format_ntp():dayname = ["Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday",]monthname = ["January","February","March","April","May","June","July","August","September","October","November","December" ]now = ntp.datetimereturn f"{dayname[now.tm_wday]}, {now.tm_mday} {monthname[now.tm_mon-1]} {now.tm_year} - {now.tm_hour:02}:{now.tm_min:02}:{now.tm_sec:02}"# Write the HTML page body as a Python 3 'f' string for advanced formatting.## Double curly braces {{ and }} are used when HTML needs single braces for HTML# page elements such as CSS styling.font_family = "sans-serif"def webpage():html = f"""<!DOCTYPE html><html><head><meta http-equiv="Content-type" content="text/html;charset=utf-8"><meta name="viewport" content="width=device-width, initial-scale=1"><style>html{{font-family: {font_family};background-color: #FFFFFF;display:inline-block;margin: 0px auto;text-align: center;}}h1{{color:#D35F8D;word-wrap: break-word;font-size: 35px;}}h2{{color:#D35F8D;word-wrap: break-word;font-size: 20px;}}p{{font-size: 1.5rem;word-wrap: break-word;}}.button-red{{font-family: {font_family};display: inline-block;width: 99%;background-color: #DC143C;border: none;border-radius: 4px;color: white;padding: 16px 40px;text-decoration: none;font-size: 30px;margin: 2px;cursor: pointer;}}.button-green{{font-family: {font_family};display: inline-block;width: 99%;background-color: #228B22;border: none;border-radius: 4px;color: white;padding: 16px 40px;text-decoration: none;font-size: 30px;margin: 2px;cursor: pointer;}}p.dotted {{margin: auto;width: 90%;font-size:25px;text-align: center;}}</style></head><body><title>Pico W LED Control</title><h1>Pico W LED Control</h1><form accept-charset="utf-8" method="POST"><button class="button-green" name="LED ON" value="ON" type="submit">LED ON</button></a><button class="button-red" name="LED OFF" value="OFF" type="submit">LED OFF</button></a></form><h2>CircuitPython Version: {os.uname().version.split(' ')[0]}<br/>{format_ntp()}</h2></body></html>"""return html# Default route static IP@server.route("/")def base(request: Request):  # pylint: disable=unused-argumentreturn Response(request, f"{webpage()}", content_type='text/html')# Determine which button was pressed and execute that button's associated# action.@server.route("/", POST)def buttonpress(request: Request):raw_text = request.raw_request.decode("utf8")print(raw_text)## If the led on button was pressed...if "ON" in raw_text:led.value = True## If the led off button was pressed...if "OFF" in raw_text:led.value = Falsereturn Response(request, f"{webpage()}", content_type='text/html')print(" Starting HTTP server...")try:server.start(str(wifi.radio.ipv4_address))print(f" Listening on http://{wifi.radio.ipv4_address}")## If the server fails to start then reset the Pico W.# If there is a hardware failure then this can put the software into a# boot loop. That's why the time.sleep(5) is there so that a Ctrl C can exit# at the REPL during development.#except OSError:print(" !!! OSError Exception, Waiting !!!")time.sleep(5)print(" !!! OSError Exception, Restarting !!!")microcontroller.reset()print(" Start polling...")## DO NOT hard code the while loop as True,# instead provide a test and exit if something goes wrong.#is_healthy = True;while is_healthy:try:# Poll for incoming requests.server.poll()except Exception as e:print(e)is_healthy = Falsecontinue

circuit python 9.1 beta 2

whbeebe
CircuitPython web page hosted on version 9.1.0 beta.2

The CircuitPython group ( https://circuitpython.org/ ) has now released the third beta of the 9.1 version of CircuitPython.  This is beta 2; they start at beta 0, which is different than most folks, who start at 1. Whatever, betas are betas, which are feature complete but not reasonably bug free.

All this is being hosted on a Raspberry Pi Pico W, the version that comes with WiFi support built in. I’ve been working with this combination for a while now. I did not originate the code at the end of this post, but copied it from an Adafruit project which I can’t recall and can’t locate on their site. I have stripped it down to its bare essentials, which is to simply run the web server and provide a way to turn the built-in LED on or off. I’ve done a bit of code cleanup to make it easier to extend and experiment with. Consider the code a starting point for something bigger. You will need to copy the adafruit_httpserver library onto the Pico device. You’ll find those libraries just a click away on the CircuitPython page. You’ll also need to create a settings.toml file that is resident with code.py. What to put into that file is documented in the source listing, in a comment block starting at line 18.

I’ve used both CircuitPython and MicroPython extensively. I have a MicroPython build environment for Espressif ESP32-S3 and ESP32-C3 and -C6 boards on my Linux development system. As much as I use MicroPython, I like CircuitPython because they made it much simpler to update the CircuitPython runtime as well as edit the embedded Python code. When a CircuitPython device is plugged into your computer it comes up as a file device, much like a thumb drive. All you have to do is run a communication application like minicom to talk to the device via its USB port, while you can use whatever editor you want on the source, on the device’s exposed filesystem. Every time you save an edit, the CircuitPython detects the change and restarts it automatically. Thus prototyping with CircuitPython can be a lot simpler than MicroPython.

import osimport timeimport ipaddressimport wifiimport socketpoolimport boardimport microcontrollerfrom digitalio import DigitalInOut, Directionfrom adafruit_httpserver import Server, Request, Response, POST# On-device LED setupled = DigitalInOut(board.LED)led.direction = Direction.OUTPUTled.value = False# Connect to a local WiFi access point.# Because this code is running in a CircuitPython 9 or later environment,# it requires a settings.toml file be created with at least the following# five lines:## AP_SSID = "WIFI SSID"# AP_PASSWORD = "WIFI PASSWORD"# STATIC_IP = "IP4 dotted IP address"# GATEWAY = "192.168.0.1"# DEBUG = "True" ## DEBUG can be either True or False.ipv4 =  ipaddress.IPv4Address(os.getenv('STATIC_IP'))netmask =  ipaddress.IPv4Address("255.255.255.0")gateway =  ipaddress.IPv4Address(os.getenv('GATEWAY'))wifi.radio.set_ipv4_address(ipv4=ipv4,netmask=netmask,gateway=gateway)wifi.radio.connect(os.getenv('AP_SSID'), os.getenv('AP_PASSWORD'))print(" Connected to WiFi access point...")pool = socketpool.SocketPool(wifi.radio)server = Server(pool, "/static", debug=os.getenv('DEBUG'))# Write the HTML page body as a Python 3 'f' string for advanced formatting.## Double curly braces {{ and }} are used when HTML needs single braces for HTML# page elements such as CSS styling.font_family = "sans-serif"def webpage():html = f"""<!DOCTYPE html><html><head><meta http-equiv="Content-type" content="text/html;charset=utf-8"><meta name="viewport" content="width=device-width, initial-scale=1"><style>html{{font-family: {font_family};background-color: #FFFFFF;display:inline-block;margin: 0px auto;text-align: center;}}h1{{color:#D35F8D;word-wrap: break-word;font-size: 35px;}}h2{{color:#D35F8D;word-wrap: break-word;font-size: 20px;}}p{{font-size: 1.5rem;word-wrap: break-word;}}.button-red{{font-family: {font_family};display: inline-block;width: 99%;background-color: #DC143C;border: none;border-radius: 4px;color: white;padding: 16px 40px;text-decoration: none;font-size: 30px;margin: 2px;cursor: pointer;}}.button-green{{font-family: {font_family};display: inline-block;width: 99%;background-color: #228B22;border: none;border-radius: 4px;color: white;padding: 16px 40px;text-decoration: none;font-size: 30px;margin: 2px;cursor: pointer;}}p.dotted {{margin: auto;width: 90%;font-size:25px;text-align: center;}}</style></head><body><title>Pico W LED Control</title><h1>Pico W LED Control</h1><form accept-charset="utf-8" method="POST"><button class="button-green" name="LED ON" value="ON" type="submit">LED ON</button></a><button class="button-red" name="LED OFF" value="OFF" type="submit">LED OFF</button></a></form><h2>CircuitPython Version: {os.uname().version.split(' ')[0]}<br/>{format_ntp()}</h2></body></html>"""return html# Default route static IP@server.route("/")def base(request: Request):  # pylint: disable=unused-argumentreturn Response(request, f"{webpage()}", content_type='text/html')# Determine which button was pressed and execute that button's associated# action.@server.route("/", POST)def buttonpress(request: Request):raw_text = request.raw_request.decode("utf8")print(raw_text)## If the led on button was pressed...if "ON" in raw_text:led.value = True## If the led off button was pressed...if "OFF" in raw_text:led.value = Falsereturn Response(request, f"{webpage()}", content_type='text/html')print(" Starting HTTP server...")try:server.start(str(wifi.radio.ipv4_address))print(f" Listening on http://{wifi.radio.ipv4_address}")## If the server fails to start then reset the Pico W.# If there is a hardware failure then this can put the software into a# boot loop. That's why the time.sleep(5) is there so that a Ctrl C can exit# at the REPL during development.#except OSError:print(" !!! OSError Exception, Waiting !!!")time.sleep(5)print(" !!! OSError Exception, Restarting !!!")microcontroller.reset()print(" Start polling...")## DO NOT hard code the while loop as True,# instead provide a test and exit if something goes wrong.#is_healthy = True;while is_healthy:try:# Poll for incoming requests.server.poll()except Exception as e:print(e)is_healthy = Falsecontinue