Unanswered Questions
136 questions with no upvoted or accepted answers
5
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SPI between Master arduino and Slave arduino
How can I send the string from Slave SPI to Master SPI?
I want to write code in Bare Metal.
The problem which I am facing is I can't make out what will be my blocking function in Master SPI code when ...
CommunityBot
- 1
3
votes
0
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443
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Raspberry pi pico (Arduino core) not initialising SPI correctly for NRF24l01
I'm working on a project where i have a Raspberry pi Pico connected to a NRF24l01+ to send some data.
However i'm not recieving any data on the reciever and i think that its because the SPI bus is not ...
- 1,554
3
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0
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ESP32-C3 SPI Class documentation/features?
ESP32-C3 has a nice feature called GPIO Matrix which allows to map most of it's peripherals to any GPIO pin. And it has feature called IO_MUX which allows direct & faster operations for some of ...
- 131
3
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238
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Black screen when using higher SPI-speed for RA8857 LCD-controller
I'm using an Arduino Due that talks via SPI to an LCD (800x480) with the RA8875 controller chip.
The most recent datasheet I could find is: RA8875 datasheet.
Everything works as expected when using ...
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3
votes
0
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859
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SPI register read returns 0x00 or 0xff
I am trying to interface a Arduino Uno with an ASM330LHH using SPI. Whenever I try to read any register, I either get 0xff or 0x00 on the serial monitor
The code I am using:
#include <SPI.h>
#...
3
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0
answers
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How to use SPI to set/ read registers for a sensor (Avoiding need for Github Lib)
Ok so as some readers might have seen, my current project involves using MPU's. The idea is sending data via CAN bus to a controlling MCU to then send to a raspberry pi to perform the calculations ...
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3
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0
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234
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Scheduling and BLE Read on demand
I'm building a data logging device with BLE capability using RFduino.
Sensors are read using timer interrupt to a buffer. When the buffer is full, then the whole buffer is written to SD card.
At the ...
- 2,522
3
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514
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SPI communication between two Ethernet Shields (W5100)
I am a newbie to the world of IoT, I want to ask...
Is it possible to connect two Ethernet shields with SPI? And if yes, how can I codes them?
I have reference from http://www.gammon.com.au/spi and ...
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3
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0
answers
642
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Do software SPI read from a register using shiftin()
How to read from a register using software SPI, presumably shiftin()?
It works using the builtin SPI library + hardware SPI.
I seem to be able to write but not read using manual shiftin()/shiftout()...
- 3,228
3
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0
answers
982
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Read from the SD card - ACMD41 times out
I'm trying to read from the SD card using an Arduino Pro Mini (3.3 V), Pololu micro-SD reader (the 3.3V one) over a SPI protocol.
I've tried both the SD library from Arduino SDK, and the Adafruit one....
- 2,522
2
votes
0
answers
120
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Slow I2C communication
To collect temperature and BPM, I connected a max30101 in my Heltec WiFi kit V3 with ESP32. The data collected are stored in arrays to extract statistical features from signals which an algorithm will ...
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2
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0
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348
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Ability to connect 2 or more w5500 Modules and deal with them as objects
I wish to create a rudimentary ethernet in/out - switch/hub where I can (sort of) daisy chain my boards. (I don't wish to use a ethernet switch/router/hub)
One port would be acting as server
The ...
- 650
2
votes
0
answers
264
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SD card breakout sometimes does not initialise (SPI connection - Teensy 3.2)
I have connected this Adafruit SD Breakout to a Teensy 3.2 over SPI. Because Teensy 3.2 is 3.3 V, I've connected the 3.3 V pin of the Teensy to the 3V pin of the SD breakout.
See sketch below. I'm ...
- 185
2
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0
answers
387
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ESP32DevkitC-V4 interfacing ADS8698 (18 bit ADC)
I am currently working on an SPI interface to measure the voltage of an amplified sensor bridge signal. I am using an ESP32 module to control the device. Since I am logging the data to an SD card, I ...
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2
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0
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614
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Why can't an Arduino/ATmega328 act as an SPI slave at anywhere approaching the maximum speed claimed in the datasheet?
The ATmega328 datasheet claims a maximum SPI slave speed of Fosc/4. For a chip clocked at 20MHz, that would be 5Mbps.
However, my tests show that even with no processing whatsoever in the interrupt (...
