Arduino newsletter

Top new questions this week:

Sending uint16_t over I2C

How do you transmit and read a uint16_t over I2C? I'm trying to read two uint16_t values from a slave device, and I'm seeing nonsensical readings. This is the code on my slave Arduino Uno: #include ...

arduino-uno i2c

asked by Cerin 4 votes answered by KIIV 2 votes

Pinball - "All Lanes Lit" Bonus score is not behaving as expected

I'm trying to build a (very basic) pinball machine with an Arduino Uno. This part of the code will detect when a ball passes 3 lanes. When a lane is passed, it will activate the lane(laneState), ...

arduino-uno arduino-ide

asked by Cagy79 3 votes answered by sa_leinad 1 vote

Check if Arduino is connected to PC

I have been searching around the Internet to find if there is a way to check if an Arduino is connected to a PC or not. For example: if my PC is turned on, the Arduino will listen to any serial ...

serial arduino-nano sketch

asked by TheKayneGame 2 votes

Multiple MuxShield 2's connected to a single Arduino Mega

I am working on a project and need alot of toggle buttons to control various things around the house. I connected 5 MuxShield 2's to my Arduino Mega. The first two will serve as inputs and the last ...

c++ multiplexer

asked by Jochim 2 votes

Connecting Saleae Logic 8 to MISO (pin 12) on Uno 3 w/ NRF24L01+ halts program

I have an NRF24L01+ with the base module (regulates voltage) connected to an Arduino Uno 3. I'm using the tmrh20 NRF24 library and am running one of the example programs. I'm trying to sniff the SPI ...

arduino-uno spi nrf24l01+

asked by Brennan Cheung 2 votes

Ooops, no LSM303 detected ... Check your wiring!

History I have an Adafruit 10DOF IMU Breakout which has been working on my Mega for some time. This morning my program did not run so I starting troubleshooting. Scenario I eventually plugged the ...

adafruit accelerometer

asked by Jacksonkr 2 votes

What is the maximum length an Interrupt Service Routine?

In general, what's the maximum length of instructions that can be included in an Interrupt Service Routine? The docs say an ISR should be "as short and fast as possible", but that's bit vague. For ...

interrupt isr

asked by Cerin 2 votes answered by Mikael Patel 2 votes

Greatest hits from previous weeks:

How to communicate the Arduino board with SIM900?

I have a problem. I bought a SIM900 board, but I can not connect there with the Arduino. To send AT commands on the serial the SIM900 doesn't respond, but the LED indicating that the network is on. ...

gsm

asked by Avelino 1 vote answered by Avelino 1 vote

Arduino not detected On El Capitan Public Beta 6

Since I updated to El Capitan Public Beta, my Arduino Uno doesn't show up in the serial devices list. The System Information utility shows an Arduino connected on the USB port (as 'Communication ...

arduino-uno serial ftdi osx

asked by duci9y 3 votes answered by Jake C 4 votes

Can you answer these?

Esp8266 not working

I connected all the pins as in datasheet, except ch_pd. But when I connect ch_pd to 3.3 V , the red light on esp8266 goes dim. I used 3.3 V, 250 mA power supply. What is the reason for this?

esp8266

asked by Jaison 1 vote

Attempt stacking 'CAN-BUS' and 'USB Host' Shields on Mega 2560

I've run into a case of 'In theory it works, but in reality'.... I'm using the CAN-BUS Shield V1.2 from Seeed studio. Many things are written in broken english, so I'm starting to wonder if I can ...

arduino-mega shields usb spi can-bus

asked by wookie4747 2 votes

How to prevent Wire.requestFrom from hanging?

I'm trying to read data from an Arduino Uno I2C slave via Wire.requestFrom() on an Arduino Uno master. The slave's onRequest handler is simply: void I2C_Send() { byte myArray[4]; myArray[0] = ...

i2c wire-library

asked by Cerin 1 vote