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by jayben
Wed Jul 21, 2021 11:15 am
Forum: General
Topic: Pi Pico - the most user un-friendly MCU?
Replies: 243
Views: 6972

Re: Pi Pico - the most user un-friendly MCU?

A major point of our SDK structure and build system is that code is not inserted unless it is needed - there is very little fluff in there at all. printf might be a minor exception, as its almost always needed during development, but I believe it can be turned off easily (will need to check how to ...
by jayben
Wed Jul 21, 2021 9:21 am
Forum: General
Topic: Pi Pico - the most user un-friendly MCU?
Replies: 243
Views: 6972

Re: Pi Pico - the most user un-friendly MCU?

Our system already works and does a fine job. I agree that it works; you ask the system to make a program, and it does that. Also it does a fine job for some use-cases, most notably the novice programmer who wants to stitch together some source code to achieve a simple task. However, when trying to...
by jayben
Tue Jul 20, 2021 9:40 am
Forum: C/C++
Topic: Understanding Low Level SPI communications [Help]
Replies: 7
Views: 401

Re: Understanding Low Level SPI communications [Help]

The scope decode is still completely wrong; those low-amplitude (roughly 1 volt) pulses are caused by the clock & MOSI signals being carried over by capacitative coupling with the MISO line, as it is floating (not being driven by the CPU or ADC). So this proves that the command you are sending i...
by jayben
Mon Jul 19, 2021 12:00 pm
Forum: Other RP2040 boards
Topic: RP2040 replacing future Pi components
Replies: 5
Views: 266

Re: RP2040 replacing future Pi components

An RP2040 could be used to support real-time I/O on the Pi, such as scanning i2c or SPI devices. However, without a high-speed link back to the Pi CPU, this would be of limited use. I suspect the temptation would be to use a USB link between the two, since that supports data transport & device p...
by jayben
Mon Jul 19, 2021 8:26 am
Forum: C/C++
Topic: Understanding Low Level SPI communications [Help]
Replies: 7
Views: 401

Re: Understanding Low Level SPI communications [Help]

Doing a quick decode by eye of the scope trace, it looks like the returned data is 00000001 11101000 00000000 The data sheet is at https://ww1.microchip.com/downloads/en/DeviceDoc/21298e.pdf If you look at the response format defined in figure 5-1, you'll see there are 6 dummy bits (covering the out...
by jayben
Sun Jul 18, 2021 8:32 am
Forum: General
Topic: W10 Says my Pico is 'malfunctioning'
Replies: 2
Views: 198

Re: W10 Says my Pico is 'malfunctioning'

Load flash_nuke.uf2, then re-load MicroPython.
by jayben
Sat Jul 17, 2021 9:22 am
Forum: General
Topic: Pi Pico - the most user un-friendly MCU?
Replies: 243
Views: 6972

Re: Pi Pico - the most user un-friendly MCU?

In my experience, cmake does the opposite ; it includes all sorts of stuff that I haven't asked for, and don't need. Have you actually looked at the output of cmake in verbose mode? You'll be amazed as to what is included. The whole point of microcontroller programming is to give the programmer dire...
by jayben
Thu Jul 15, 2021 8:26 pm
Forum: General
Topic: Pi Pico - the most user un-friendly MCU?
Replies: 243
Views: 6972

Re: Pi Pico - the most user un-friendly MCU?

To answer the question in the title: no, there are far more un-friendly MCUs. Clearly you have no experience of badly-documented devices with obscure hardware features and buggy compilers. Furthermore, the MicroPython system works well, and is an excellent way of programming the device, that is very...
by jayben
Sun Jul 11, 2021 8:39 am
Forum: General discussion
Topic: Shock while touching the metal parts of usb port in raspberry pi 4
Replies: 41
Views: 1380

Re: Shock while touching the metal parts of usb port in raspberry pi 4

Not as unlikely as you think; I've destroyed the I/O on 2 Pi boards by mistakenly connecting them to a sensor that was connected to earth, rather than the Pi ground. Since there were no other ground connections, the Pi was effectively floating at a high voltage (as described by the OP) and the senso...
by jayben
Sat Jul 10, 2021 3:27 pm
Forum: Beginners
Topic: How to change LED on fixed circuit?
Replies: 6
Views: 232

Re: How to change LED on fixed circuit?

Look for LED replacement bulbs and holders, e.g. https://uk.rs-online.com/web/c/?searchTerm=ba9s

However, if you don't exceed the maximum current, the LED will probably outlast its usefulness by a long way, so just solder the device in.
by jayben
Fri Jul 09, 2021 8:37 am
Forum: General
Topic: RP2040 with internal oszilator
Replies: 6
Views: 290

Re: RP2040 with internal oszilator

See the RP2040 datasheet, section 2.17 "Ring Oscillator"

However, unlike the Atmel device, it has a very wide range of operation: "During boot the ROSC runs at a nominal 6.5MHz and is guaranteed to be in the range 1.8MHz to 12MHz" so it can't be used as a clock for serial or USB.
by jayben
Thu Jul 08, 2021 7:22 pm
Forum: Compute Module
Topic: Tests to help validate board
Replies: 5
Views: 333

Re: Tests to help validate board

You ask about testing for 'strict compliance with the specs', and if this is really what you want, you'll need to hire some really expensive test equipment, or pay a certified test house to do a large battery of tests - and it won't be cheap. However, in my experience, such testing is very rarely (i...
by jayben
Thu Jul 08, 2021 8:14 am
Forum: HATs and other add-ons
Topic: Capacitive touch and wire length
Replies: 7
Views: 387

Re: Capacitive touch and wire length

For this to work you'd have to minimise cross-coupling & cabling, so maybe stacking the button board behind the sensor board might work, if you use a short pin-and-socket connection between them, and not cabling - take a look at the data sheet for the touch sensor IC you are using, and it might ...
by jayben
Tue Jul 06, 2021 7:50 pm
Forum: Other projects
Topic: Making: How to fill the gap
Replies: 3
Views: 257

Re: Making: How to fill the gap

When doing my first PCB design, I used an autorouter to do the main routing, then tidied up the resulting mess by hand - and as time progressed, I was doing more and more tidying up, less and less autorouting, such that I no longer bother with the autorouter, and do everything by hand. I understand ...
by jayben
Tue Jul 06, 2021 7:14 pm
Forum: HATs and other add-ons
Topic: Capacitive touch and wire length
Replies: 7
Views: 387

Re: Capacitive touch and wire length

Touch buttons rely on detecting very small changes in capacitance, and you're adding an large chunk of fixed capacitance in the wiring, so it is unlikely to work reliably. This problem will be compounded if the buttons & wiring are grouped closely together, as there will be a lot of inductive &a...
by jayben
Mon Jul 05, 2021 10:04 am
Forum: General
Topic: Can the Picoprobe provide access to multiple SWD targets at once?
Replies: 3
Views: 233

Re: Can the Picoprobe provide access to multiple SWD targets at once?

It wouldn't be difficult for a modified Picoprobe to drive multiple Picos, as the SWD-over-USB protocol is non-standard, so a minor addition could provide a command to select one of several target devices.

If you'd like to do some experimentation with SWD, see my blog https://iosoft.blog/picoreg/
by jayben
Mon Jul 05, 2021 9:50 am
Forum: General discussion
Topic: How to enable real time Communication between Raspberry pi and a mobile application
Replies: 5
Views: 333

Re: How to enable real time Communication between Raspberry pi and a mobile application

..or maybe a simple Web server (such as Cherrypy) that returns JSON data to the mobile app..
by jayben
Mon Jul 05, 2021 9:43 am
Forum: General discussion
Topic: Charge a Phone off the Pins?
Replies: 8
Views: 284

Re: Charge a Phone off the Pins?

In theory, you can just use a higher-current 5V supply to feed both the Pi and the phone, but the Pi can be quite fussy about its supply, so you'll need to watch out for the voltage drop in the wiring, and the possibility of overloading the supply when the phone takes its full charging current.
by jayben
Wed Jun 30, 2021 12:09 pm
Forum: SDK
Topic: Generating .h files (and other stuff) from the .SVD file...
Replies: 2
Views: 232

Re: Generating .h files (and other stuff) from the .SVD file...

I couldn't find any simple tools to decode & display SVD files, so created my own parser & GUI in Python, which might be of help: https://iosoft.blog/picoreg/
by jayben
Wed Jun 30, 2021 11:55 am
Forum: Networking and servers
Topic: cant set up webserver with web socket...stuck
Replies: 5
Views: 266

Re: cant set up webserver with web socket...stuck

The Websocket protocol is quite complicated to set up, here is a simple explanation & demonstration in Python: https://iosoft.blog/websocket-programming/
by jayben
Wed Jun 30, 2021 11:45 am
Forum: Troubleshooting
Topic: Ping Spikes with Raspberry Pi Zero W
Replies: 7
Views: 207

Re: Ping Spikes with Raspberry Pi Zero W

I've seen similar time delays with a UDP application running on a ZeroW, and guessed there might be 2 possible sources; the WiFi doing a channel scan, and/or the 2.4 GHz RF synthesiser doing a calibration cycle. I think somewhere buried in the BCM43438 data sheet they say it recalibrates every few m...
by jayben
Tue Jun 29, 2021 10:38 am
Forum: Off topic discussion
Topic: is there a 100' deep water temperature gauge?
Replies: 2
Views: 437

Re: is there a 100' deep water temperature gauge?

My starting point would be a 1-wire temperature sensor, which is available in a variety of housings, e.g. https://datanab.com/collections/1-wire-temperature-sensors I have no idea what will happen when the sensor is immersed in deep water, but it'd be worth a try. You'd probably be OK-ish with 100 f...
by jayben
Fri Jun 25, 2021 1:29 pm
Forum: Automation, sensing and robotics
Topic: Point A to B self driving drink delivery bot
Replies: 2
Views: 312

Re: Point A to B self driving drink delivery bot

The key question is whether the robot is operating in an unknown or known environment. If unknown, then a LIDAR Simultaneous Location and Mapping (SLAM) system would do what you want, but it is going to be quite complex, involving cutting-edge techniques, so I'd suggest you do some detailed research...
by jayben
Thu Jun 24, 2021 7:10 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Problem with PICAN2 and SPI interface
Replies: 3
Views: 277

Re: Problem with PICAN2 and SPI interface

You are confusing two completely separate things: the SPI frequency and the CAN data rate. You need to find out what CAN data rate the motor controller is expecting; this is normally 1 Mbit/s or less. Then you use the PicCAN device driver to set that rate on the CAN interface board. It doesn't matte...
by jayben
Sat Jun 19, 2021 10:06 am
Forum: Other projects
Topic: Monitoring a Heat-Recovery Ventilator in a Home Control System
Replies: 4
Views: 350

Re: Monitoring a Heat-Recovery Ventilator in a Home Control System

You don't say if the data is async or synchronous (i.e. with a separate clock line) but I assume the former. The smallest time-value of 0.5 msec does imply a baud rate around 2000; if you measure the width accurately, does it correspond to 2400 baud? Is there evidence of start and stop bits, assumin...

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