Search found 31 matches

by stoikos
Wed Apr 22, 2020 6:46 am
Forum: General Discussion
Topic: Strapping Pins explanation
Replies: 5
Views: 71009

Re: Strapping Pins explanation

you can use a line buffer like SN74AHC125D tied to the EN via a voltage supervisor like MAX810TTRG
by stoikos
Mon May 06, 2019 6:14 pm
Forum: General Discussion
Topic: is there any issue using io0/io4 for i2c?
Replies: 7
Views: 9523

Re: is there any issue using io0/io4 for i2c?

This is the code that I am running. I put a scope on IO0 and I get the attached signal. the same program on another pin works like a charm. void task_i2cscanner(void *ignore) { vTaskDelay(1000 / portTICK_PERIOD_MS); ESP_LOGD("Sensor", ">> i2cScanner"); i2c_config_t conf; conf.mode = I2C_MODE_MASTER;...
by stoikos
Wed Apr 10, 2019 3:24 am
Forum: General Discussion
Topic: is there any issue using io0/io4 for i2c?
Replies: 7
Views: 9523

Re: is there any issue using io0/io4 for i2c?

there are not enough pins on esp32. I am already using port expanders, multiple multiplexers on that pcb. I need to make them work :) I will look with my trusted rigol. I was trying to determine if there is something internal that prohibits them to be used as i2c. they have internal pullups, they ar...
by stoikos
Wed Apr 10, 2019 3:21 am
Forum: ESP-IDF
Topic: Which certificate to embed into ESP32?
Replies: 1
Views: 4520

Re: Which certificate to embed into ESP32?

the certificate chain that validates your server certificate. Most likely the root certificate from lets encrypt + any intermediate used to singe it. look at https://stackoverflow.com/questions/25482199/verify-a-certificate-chain-using-openssl-verify you dont need to embed the certifcate from your s...
by stoikos
Tue Apr 09, 2019 2:18 pm
Forum: General Discussion
Topic: is there any issue using io0/io4 for i2c?
Replies: 7
Views: 9523

Re: is there any issue using io0/io4 for i2c?

Hi,
I know how they function, nevertheless in the esp32 docs they say that after boot they behave like normal pins. I do use them for the boot process but it doesnt seem to be working, while the same software when its using other pins is working
by stoikos
Tue Apr 09, 2019 5:24 am
Forum: General Discussion
Topic: is there any issue using io0/io4 for i2c?
Replies: 7
Views: 9523

is there any issue using io0/io4 for i2c?

I am trying to use IO0 for SDA and IO4 for SCL in I2C. I have tried with 4.7k external pullups in both pins and no pullups as well. I2cscanners fail to connect to sensors. When I am using other pins everything works fine. Any ideas?
by stoikos
Fri Feb 15, 2019 5:36 am
Forum: ESP-IDF
Topic: how can i correctly use sensor_vn and sensor_vp as input?
Replies: 0
Views: 4634

how can i correctly use sensor_vn and sensor_vp as input?

Hi, I am trying to use sensor_vn and sensor_vp as input, with values coming from an adc chip (which uses data and clock pins). I haven't added any pullup or pull down resistors. looking through the forum I have found and implemented this code. I am aware the bug about gpio39 firing where some periph...
by stoikos
Thu Dec 20, 2018 7:23 pm
Forum: ESP-IDF
Topic: barcode reader using esp32 wrover - is it feasible?
Replies: 2
Views: 6176

Re: barcode reader using esp32 wrover - is it feasible?

I have some requirements that narrow down my selection of input methods to use. a. device must be able to recognize barcodes on a curved surface (like a bottle) b. bottles will be on a conveyor belt c. low light environment. no external light permitted. d. there may be people looking into the device...
by stoikos
Wed Dec 19, 2018 10:57 pm
Forum: ESP-IDF
Topic: barcode reader using esp32 wrover - is it feasible?
Replies: 2
Views: 6176

barcode reader using esp32 wrover - is it feasible?

Hi,
Is it feasible to have a barcode reader device based on esp32? is there a barcode decode library that I can compile ? any ideas or suggestions?
by stoikos
Sat Nov 24, 2018 10:36 pm
Forum: ESP-IDF
Topic: how to truncate a file in spiffs?
Replies: 1
Views: 4150

how to truncate a file in spiffs?

I would like to truncate a file in spiffs. I have found

Code: Select all

int truncate(const char *path, off_t length)
in vfs and

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f_truncate()
in fatbut I am not sure I have to to use

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spiffs_object_truncate()
and how