Search found 139 matches

by meowsqueak
Thu Sep 14, 2017 6:00 am
Forum: General Discussion
Topic: What would you like to see in The Next Chip?
Replies: 309
Views: 92914

Re: What would you like to see in The Next Chip?

Angel J. wrote: + 802.15.4 hardware-assisted + software implementation for Zigbee / OpenThread / ...
Second this - support for 6LoWPAN specifically.
by meowsqueak
Mon Sep 11, 2017 8:26 am
Forum: ESP32 IDF
Topic: Pulse Counter initialisation overrides GPIO pull mode
Replies: 0
Views: 737

Pulse Counter initialisation overrides GPIO pull mode

I'm working with the Pulse Counter and I ran into an interfacing problem. I'm using a voltage divider to precondition a weak 4.4V signal for 3.3V range and had planned to use the ESP32 GPIO in hi-impedance (floating) mode. However I observed with my oscilloscope that the GPIO I am using for a signal...
by meowsqueak
Wed Sep 06, 2017 10:03 pm
Forum: General Discussion
Topic: Pulse counter controlled by hardware timing for frequency measurement
Replies: 22
Views: 7215

Re: Pulse counter controlled by hardware timing for frequency measurement

Thanks Ivan, that sounds like a good way to do it - I'll try it out. I assume I can use an externally wired GPIO, rather than GPIO20, for testing purposes via scope?
by meowsqueak
Wed Sep 06, 2017 7:20 am
Forum: General Discussion
Topic: Pulse counter controlled by hardware timing for frequency measurement
Replies: 22
Views: 7215

Pulse counter controlled by hardware timing for frequency measurement

Is there a way to connect the output of one of the general purpose timers to the control signal of the Pulse Counter? What I want to do is count incoming pulses for a precise amount of time, then generate an interrupt so that my application can read the result from the counter. This is in order to g...
by meowsqueak
Wed Sep 06, 2017 4:25 am
Forum: General Discussion
Topic: Advice on application architecture - Sensors/WiFi/MQTT
Replies: 13
Views: 4161

Re: Advice on application architecture - Sensors/WiFi/MQTT

Thanks for the link. So it sounds like it used to work, and now it doesn't due to a software change. Hopefully that gets sorted out soon. EDIT: looking at the latest commit on that file, I think I understand better now - that `PIN_INPUT_ENABLE()` call is to work around the issue you've linked. It do...
by meowsqueak
Wed Sep 06, 2017 2:40 am
Forum: General Discussion
Topic: Advice on application architecture - Sensors/WiFi/MQTT
Replies: 13
Views: 4161

Re: Advice on application architecture - Sensors/WiFi/MQTT

I'm aware of the Input/Output mode that can be used for open-drain operation, but I can't see where the code sets that mode. It sets the pin to input mode as per line 200: https://github.com/nodemcu/nodemcu-firmware/blob/dev-esp32/components/platform/onewire.c#L200 I note that the RMT is set for bot...
by meowsqueak
Mon Sep 04, 2017 10:05 pm
Forum: General Discussion
Topic: LWIP read() blocks CPU
Replies: 3
Views: 1247

Re: LWIP read() blocks CPU

I've confirmed my own error by simplifying my code, switching to "single CPU" mode, and also printing the Core ID to be sure, and a blocking read does not suspend all tasks on the CPU. I think my original problem was related to task priority or a blocked queue. Thanks for the response and sorry for ...
by meowsqueak
Mon Sep 04, 2017 6:08 am
Forum: General Discussion
Topic: Advice on application architecture - Sensors/WiFi/MQTT
Replies: 13
Views: 4161

Re: Advice on application architecture - Sensors/WiFi/MQTT

After realising above that only the read/write bit transactions are timing sensitive and need protection, I moved my top-level taskENTER_CRITICAL calls to wrap just the bit read/write - this means that interrupts get disabled/enabled much more often, but for a significantly shorter period of time ov...
by meowsqueak
Mon Sep 04, 2017 5:34 am
Forum: General Discussion
Topic: Advice on application architecture - Sensors/WiFi/MQTT
Replies: 13
Views: 4161

Re: Advice on application architecture - Sensors/WiFi/MQTT

https://github.com/nodemcu/nodemcu-firmware/blob/dev-esp32/components/platform/onewire.c There's one thing I don't understand about that code - when reading bits around line 378 the pin is put into INPUT mode (via onewire_rmt_attach_pin, line 200), then at 381 the wire is put into open-drain mode, ...
by meowsqueak
Mon Sep 04, 2017 5:13 am
Forum: General Discussion
Topic: Advice on application architecture - Sensors/WiFi/MQTT
Replies: 13
Views: 4161

Re: Advice on application architecture - Sensors/WiFi/MQTT

https://github.com/nodemcu/nodemcu-firmware/blob/dev-esp32/components/platform/onewire.c Thanks for that - looking at the code I can see that it uses the RMT to handle each "bit slot" - that makes a lot more sense as I was thinking that I needed to protect the entire byte as "time critical" - but i...

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