Search found 30 matches

by Greg Corson
Tue Apr 30, 2019 8:46 am
Forum: ESP32 IDF
Topic: Reading from SPI Accelerometer and networking out data at 2000hz
Replies: 2
Views: 118

Re: Reading from SPI Accelerometer and networking out data at 2000hz

This is part of an imu test rig so it needs to work with a variety of imu. This rig needs to sample several imu at once so they can be compared Regardless, even fifos generate an interrupt and then need to be read on a fairly regular schedule (when the sample rate is 2k) so I’m wondering if the read...
by Greg Corson
Tue Apr 30, 2019 12:15 am
Forum: ESP32 IDF
Topic: Reading from SPI Accelerometer and networking out data at 2000hz
Replies: 2
Views: 118

Reading from SPI Accelerometer and networking out data at 2000hz

I'm working on a setup to get data from an SPI accelerometer/gyro chip (IMU) and send the data out on WiFi over UDP or TCP. The main issue is I need to read from the SPI IMU at around 2000hz, these reads take 40-100us. I'm seeing non-blocking calls to TCP or UDP taking 500us to 1500us, so obviously ...
by Greg Corson
Thu Apr 25, 2019 11:00 pm
Forum: ESP32 IDF
Topic: UDP packet fragmentation problem
Replies: 0
Views: 111

UDP packet fragmentation problem

I found this using the ESP32 arduino setup, but I think it will apply to the ESP IDF as well so I posted it here. The issue is how large UDP packets are being handled. When a UDP packet is bigger than the MTU (around 1.4k) it is supposed to be broken into fragments, sent over the net, and reassemble...
by Greg Corson
Thu Apr 25, 2019 10:33 am
Forum: ESP32 IDF
Topic: How to schedule task to run at 2000hz?
Replies: 2
Views: 165

How to schedule task to run at 2000hz?

I need to read an accelerometer at 2000hz with a small task that runs every 500us, reads the data from spi and saves it to a buffer. The read takes less than 50us. What is a good way to schedule this task? Seems like FreeRTOS is limited to 1ms schedules. The code needs to read the accelerometer at 2...
by Greg Corson
Tue Apr 23, 2019 8:51 pm
Forum: ESP32 IDF
Topic: Do non-blocking TCP send calls work?
Replies: 1
Views: 111

Do non-blocking TCP send calls work?

So I'm trying to send some 59 byte binary messages over TCP at between 100 and 1000hz. Eventually this will read an accelerometer/gyro at this rate and send the results over the network. For now I'm having issues with timing so I put together a quick test program using the tcpserver.c example. When ...
by Greg Corson
Tue Apr 23, 2019 8:24 pm
Forum: ESP32 IDF
Topic: Stupid enum problem....
Replies: 3
Views: 193

Re: Stupid enum problem....

Knew it was something dumb, just noticed the code was compiling as C and not C++.

Thanks for the tip!
by Greg Corson
Mon Apr 22, 2019 5:59 pm
Forum: ESP32 IDF
Topic: Stupid enum problem....
Replies: 3
Views: 193

Stupid enum problem....

Ok, maybe I'm being dense but this statement: enum command_id:uint8_t {BMI160TELEMETRY = 1, MPU9250TELEMETRY}; Compiles ok in ESP32 arduino but fails when I compile it under ESP-IDF with the following error C:/msys32/home/gcorson/esp/tcp_server/main/tcp_server.c:31:16: error: expected identifier or ...
by Greg Corson
Tue Feb 12, 2019 12:34 am
Forum: ESP32 Arduino
Topic: Is bluetooth serial HUGE or am I doing something wrong
Replies: 1
Views: 329

Is bluetooth serial HUGE or am I doing something wrong

Somehow this just doesn't seem right...when I build in bluetooth serial into my arduino app the memory use goes up by 500K!

Am I doing something wrong or is this normal? I include BluetoothSerial.h and create one BluetoothSerial object.

This is with the 1.0 release of ESP32 Arduino.
by Greg Corson
Tue Jan 15, 2019 9:14 pm
Forum: ESP32 Arduino
Topic: I2C on Sparkfun ESP32; Pull-Up resistors not working. Ideas?
Replies: 3
Views: 713

Re: I2C on Sparkfun ESP32; Pull-Up resistors not working. Ideas?

There were some wire library issues in the 1.0.0 release that caused me problems with accelerometers. Sometimes if you reset the chip when the accelerometer was in the middle of sending on I2C it would hold the bus in a state that froze I2C. Fairly soon after this was discovered there was a patch bu...
by Greg Corson
Fri Aug 10, 2018 5:22 pm
Forum: ESP32 Arduino
Topic: ARDUINO multi-core support/questions
Replies: 11
Views: 3228

Re: ARDUINO multi-core support/questions

Ah, good info. In most arduino implementations delay() is blocking, but then most arduinos don't have an RTOS like ESP32 does.

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