Search found 621 matches

by PeterR
Mon May 24, 2021 4:25 pm
Forum: General Discussion
Topic: Flashing ESP32
Replies: 2
Views: 3423

Re: Flashing ESP32

JTAG can be used to both program and debug: https://www.esp32.com/viewtopic.php?t=7956 If JTAG serves both features do I need to include USB connector and USB to UART Bridge? Well that is up to you. JTAG is relatively expensive and not exactly consumer gear. (1) you could use another style of connec...
by PeterR
Wed May 19, 2021 8:59 am
Forum: General Discussion
Topic: Reading critical I2C data
Replies: 4
Views: 4961

Re: Reading critical I2C data

Although since FreeRTOS uses a lot of critical sections I might miss the interrupt Only if you configure the interrupt as being level. Try edge. There are a few critical sections but not such that you would notice. Actually that is possibly a lie. I have seen the I2C output clock stretch for >1.2mS...
by PeterR
Wed May 19, 2021 8:51 am
Forum: General Discussion
Topic: ESP32 and Trezor firmware
Replies: 3
Views: 5637

Re: ESP32 and Trezor firmware

Thats more like it! I would suggest that you start with a spreadsheet with all the ESP pins. Next allocate hardware interfaces to those pins. Check that can map the interface to the pin. Some functions are native to certain pins. If you use the GPIO mux then that slows you down. Does your example us...
by PeterR
Tue May 18, 2021 6:02 pm
Forum: General Discussion
Topic: ESP32 and Trezor firmware
Replies: 3
Views: 5637

Re: ESP32 and Trezor firmware

You did not post a link to your source material including code base! List all the hardware interfaces you have; display, usb, wifi, ble etc. Be careful though, you must break features (Display) down into acceptable interfaces. How do you achieve 'Display'? (SPI would be one way but there are others)...
by PeterR
Tue May 18, 2021 5:48 pm
Forum: General Discussion
Topic: Reading critical I2C data
Replies: 4
Views: 4961

Re: Reading critical I2C data

Which I2C device are you using? As I understand you; (1) At initialisation you want to read the I2C device's timestamp in a low latency/no interrupts way such that you know I2C time and ESP 'world' time. (2) The I2C device stores readings in an internal FIFO. When the FIFO is full you fetch all the ...
by PeterR
Tue Apr 20, 2021 5:16 pm
Forum: General Discussion
Topic: Datasheet for CAN bus
Replies: 6
Views: 5729

Re: Datasheet for CAN bus

Wifi, Do you have the commit details? I should check that all issues have been addressed. There were at least 2 errors. (1) The driver would lock failed after overflow, reboot being the only recovery. Try switching interrupts off for 100mS and you will see. (2) Corrupt data getting through. I could ...
by PeterR
Thu Apr 15, 2021 5:03 pm
Forum: General Discussion
Topic: RTC slows down, affecting DMA and serial output
Replies: 4
Views: 4180

Re: RTC slows down, affecting DMA and serial output

How do you know that the baud rate changes? Have you measured the bit rates? A long time ago I was a little out in my UART clock and this, from time to time, allowed other effects to corrupt (being marginal already). Thing was my configuration was wrong! On the ESP32 I have seen weird I2C (not I2S) ...
by PeterR
Wed Apr 14, 2021 11:10 am
Forum: General Discussion
Topic: I2C slave simulation
Replies: 0
Views: 2114

I2C slave simulation

I have a project which has a complex analogue I2C slave device. I want to automate tests & build in some determinism. The device is a set of I2C registers. Some registers hold the analogue value, others are used to configure. We use a hard coded configuration so it is enough just to check that confi...
by PeterR
Thu Apr 08, 2021 5:46 pm
Forum: General Discussion
Topic: SPI DMA in ESP32-S2-WROOM
Replies: 8
Views: 12631

Re: SPI DMA in ESP32-S2-WROOM

Keep in mind that DMA can be counter productive for small transfers. One of my SPI channels is a cheap MPC2515 and that is a very chatty device with between 3 and 8 byte transfers. Latency & setup really kill that through put. On the short transfers I measured that no DMA was faster. Basically the S...
by PeterR
Tue Apr 06, 2021 11:29 pm
Forum: General Discussion
Topic: The future of ESP32 hardware revision(fixing annoying hardware issues?)
Replies: 7
Views: 6622

Re: The future of ESP32 hardware revision(fixing annoying hardware issues?)

Qualcomm and NXP seem to offer solutions (but still below Espressif in terms in functionality and cost) Exactly, 'you pays your money....' So (basically) finding a silicon sweet spot is very tricky! Also very tricky for anyone else to review that trade without knowing your ram/flash etc requirement...