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by jcsbanks
Fri Mar 23, 2018 3:41 pm
Forum: ESP32 IDF
Topic: RMT - simplest receive example working, but idle_threshold problem
Replies: 13
Views: 3428

Re: RMT - simplest receive example working, but idle_threshold problem

Also tried: different GPIO, different RMT channel, different CPU speed, different FreeRTOS tick rates, enabled verbose logging and checked the register is being written correctly by reading it back. The error with idle_threshold over a value between 11000 and 12000 only occurs when an input with a p...
by jcsbanks
Fri Mar 23, 2018 3:24 pm
Forum: General Discussion
Topic: Urgent Need for Pulse Width Measurement, Register/Hardware Descriptions Would Work
Replies: 13
Views: 9839

Re: Urgent Need for Pulse Width Measurement, Register/Hardware Descriptions Would Work

Was this fixed? Think I might be having the same issue here: https://www.esp32.com/viewtopic.php?f=13&t=5122 When I increase the idle_threshold to 12000 or beyond (including 65535), I get an error. I am trying to understand the error code. I get similar error codes by putting in frequencies that sho...
by jcsbanks
Fri Mar 23, 2018 12:20 pm
Forum: ESP32 IDF
Topic: RMT - simplest receive example working, but idle_threshold problem
Replies: 13
Views: 3428

RMT - simplest receive example working, but idle_threshold problem

#include "freertos/FreeRTOS.h" #include "freertos/task.h" #include "freertos/queue.h" #include "driver/rmt.h" #include "driver/periph_ctrl.h" #include "soc/rmt_reg.h" void app_main() { rmt_config_t rmt_rx = { .channel = 0, .gpio_num = 17, .clk_div = 80, //1MHz .mem_block_num = 1, .rmt_mode = RMT_MO...
by jcsbanks
Fri Mar 16, 2018 11:51 pm
Forum: Hardware
Topic: ESP-WROVER-KIT SCH-3: IO2 pulled up and down for SD card
Replies: 2
Views: 1300

ESP-WROVER-KIT SCH-3: IO2 pulled up and down for SD card

https://dl.espressif.com/dl/schematics/ESP-WROVER-KIT_SCH-3.pdf IO2 has 5K to ground and 10K to 3V3 near the SD card. I thought that IO2 is to be pulled up for SD card operation whereas this would sit at about 1.1V. IO2 uses a third transistor in the auto program circuit. Is this so that IO0 and IO2...
by jcsbanks
Wed Mar 07, 2018 1:02 pm
Forum: Hardware
Topic: About the CAN controller.
Replies: 173
Views: 105876

Re: About the CAN controller.

It might be because you are using an RTOS queue to receive. I had a similar problem on page 8 and Thomas suggested replying in an interrupt. When I did this the latency went from multiple milliseconds to less than 10 microseconds which is the clock of the Kvaser tool.
by jcsbanks
Sat Apr 15, 2017 7:30 pm
Forum: Hardware
Topic: About the CAN controller.
Replies: 173
Views: 105876

Re: About the CAN controller.

First eight packets are with a FreeRTOS task replying with an echo of packets received, so four are sent, four received. Second eight packets are with the reply in an ISR. Moving from FreeRTOS to an ISR drops the latency 20 times from average of 5.3ms to 260us.
latency.png
latency.png (18.63 KiB) Viewed 6997 times
by jcsbanks
Wed Apr 05, 2017 12:36 pm
Forum: Hardware
Topic: About the CAN controller.
Replies: 173
Views: 105876

Re: About the CAN controller.

It is working with MCP2551. Kvaser log, I sent 8 zeros in the first three packets, then 0, 52 then six zeroes in the subsequent packets and the ESP32 echoes them. The 2018 is the CAN ID, 8 is the DLC, then the payload, then the timestamp and Transmit or Receive. 0 2018 8 0 0 0 0 0 0 0 0 66.129150 T ...
by jcsbanks
Thu Mar 30, 2017 11:14 am
Forum: Hardware
Topic: About the CAN controller.
Replies: 173
Views: 105876

Re: About the CAN controller.

Connecting the D pin of the tranceiver to 3.3V, I read -1.1mV between CAN H and CAN L with the bus disconnected but with 120R termination. Connecting the D pin of the tranceiver to 0V I read 0mV between CAN H and CAN L. I should be getting a positive voltage between CAN H and CAN L in this situation...
by jcsbanks
Thu Mar 30, 2017 10:43 am
Forum: Hardware
Topic: About the CAN controller.
Replies: 173
Views: 105876

Re: About the CAN controller.

Thanks rudi. Yes I am using Kvaser Leaf Light v2 HS with OBD plug. SN65HVD230 CAN bus tranceiver (3.3V). Kvaser Leaf CAN H to SN65HVD230 CAN H. Kvaser Leaf CAN L to to SN65HVD230 CAN L. Kvaser Leaf GND pin 5 (signal ground) to to SN65HVD230 GND. I will try Kvaser Leaf GND pin 4 (chassis ground) and ...

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