Summary of Driving multiple Sparkfun 7-segment displays with an Arduino
This article details the resolution of electronics issues for a bicycle brake tester senior project, specifically focusing on interfacing multiple Sparkfun 7-segment displays with an Arduino. The author addresses common configuration errors, such as incorrect baud rates, and provides code to write numbers to several displays simultaneously. Key implementation steps include using SoftwareSerial and ensuring the TX line connects to the display's RX pin while leaving the RX line unconnected.
Parts used in the Bicycle Brake Tester:
- Arduino
- Sparkfun 7-segment displays
- SoftwareSerial library
I’m currently helping a couple of engineering students finish a senior project that didn’t get finished last year. Long story… Anyway, it’s a bicycle brake tester being built for Paul Components. The mechanical design is great, but they had trouble with the electronics.
Part of those electronics involved writing numbers to a pair of Sparkfun 7-segment displays. There’s a lot of discussion on the Sparkfun board about these: apparently they’re difficult. I had some issues making them work —baud rate, for example, which should be set to 9600 in setup() not 2400 as stated in some references— but it’s relatively straightforward once those issues are straightened out. Here’s my code, in hopes that it’ll be helpful to anyone else trying to write to several 7-segment displays simultaneously.
The serial TX line (second pin given in the SoftwareSerial declaration) should be connected to the RX pin on the corresponding Sparkfun breakout board; the RX line in the SoftwareSerial declaration should be left unconnected.
For more detail: Driving multiple Sparkfun 7-segment displays with an Arduino
- What baud rate should be set in setup()?
The baud rate should be set to 9600, not 2400. - How should the serial TX line be connected?
The serial TX line from the SoftwareSerial declaration must connect to the RX pin on the corresponding Sparkfun breakout board. - What should be done with the RX line in the SoftwareSerial declaration?
The RX line in the SoftwareSerial declaration should be left unconnected. - Can multiple 7-segment displays be driven simultaneously?
Yes, the provided code allows writing to several 7-segment displays at the same time. - Are Sparkfun 7-segment displays difficult to work with?
Yes, there is significant discussion about them being difficult, though they become straightforward once issues are resolved. - What was the main problem faced by the engineering students?
The students had trouble with the electronics, specifically writing numbers to the displays.
