https://github.com/luigif/hcsr04

Beaglebone Black PRU code for HC-SR04 sonar
https://github.com/luigif/hcsr04

assembly-language beaglebone beaglebone-black c iot pru

Last synced: 3 months ago
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Beaglebone Black PRU code for HC-SR04 sonar

• Host: GitHub
• URL: https://github.com/luigif/hcsr04
• Owner: luigif
• Created: 2014-05-02T10:46:59.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2014-10-26T18:37:45.000Z (about 10 years ago)
• Last Synced: 2024-09-30T06:05:04.440Z (3 months ago)
• Topics: assembly-language, beaglebone, beaglebone-black, c, iot, pru
• Language: OpenEdge ABL
• Homepage:
• Size: 375 KB
• Stars: 26
• Watchers: 6
• Forks: 21
• Open Issues: 2
• Metadata Files:
  • Readme: README.md

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README

        

Beaglebone Black PRU code to use HC-SR04 proximity sensor.

===

There are many examples around with Beaglebone PRU code to use an HC-SR04 sonar sensor, but most are outdated, do not work or require older beagles or older kernels. 

This repository includes everything needed to obtain a working example and can be used as a template for more complex PRU code.

Prerequisites:

	* Beaglebone Black with debian 3.8.13 bone47

	* HC-SR04 sensor

	* Dev tools (gcc, pasm, dtc, etc.) that are already included in BBB latest images.

	  (If you miss them, please upgrade from http://beagleboard.org/latest-images/)

Hardware configuration:

	* TRIGGER		P8_12 gpio1[12] GPIO44	out	pulldown		Mode: 7 

	* ECHO			P8_11 gpio1[13] GPIO45	in	pulldown		Mode: 7 *** with R 1KOhm

	* GND			P9_1 or P9_2	GND

	* VCC			P9_5 or P9_6	VDD_5V

	

	Make sure there is a 1KOhm resistor between ECHO pin and your beaglebone

	as input pins are 3.3V while sensor emits 5V

### Schematic:

	

![Schematic](hc-sr04.png?raw=true)

### To download the complete package to your Beaglebone Black:

	wget --no-check-certificate https://github.com/luigif/hcsr04/archive/master.tar.gz -O - | tar xz

### To build:

 	

 	cd hcsr04-master

	make

	

### To install driver:

	make install

	

	It will copy device tree driver to /lib/firmware and add it to the cape manager

	

### To run:

	./hcsr04

	Note: After a first successful "make install", before running the hcsr04 program, 

	you can load the driver with the install-driver.sh script.

	Depending on your needs, you can configure your operating system to run the 

	install-driver.sh script at boot.

### Example build output after running "make":

	>> Compiling Driver

	dtc -O dtb -o hcsr04-00A0.dtbo -b 0 -@ hcsr04.dts

	

	>> Generating PRU binary

	pasm -b hcsr04.p

	PRU Assembler Version 0.84

	Copyright (C) 2005-2013 by Texas Instruments Inc.

	Pass 2 : 0 Error(s), 0 Warning(s)

	Writing Code Image of 43 word(s)

	

	>> Compiling HC-SR04 example

	gcc -Wall -c -o hcsr04.o hcsr04.c

	gcc -lpthread -lprussdrv -o hcsr04 hcsr04.o

### Example output after running "./hcsr04":

	>> Initializing PRU

	>> Executing HCSR-04 code

	  1: Distance = 181.52 cm

	  2: Distance = 181.50 cm

	  3: Distance = 181.50 cm

	  4: Distance = 181.52 cm

	  5: Distance = 181.93 cm

	  6: Distance = 181.52 cm

	  7: Distance = 180.64 cm

	  8: Distance = 181.50 cm

	  9: Distance = 181.06 cm

	 10: Distance = 181.49 cm

	 11: Distance = 181.04 cm

	 12: Distance = 181.93 cm

	 13: Distance = 181.47 cm

	 14: Distance = 181.47 cm

	 15: Distance = 181.91 cm

	 16: Distance = 181.91 cm

	 17: Distance = 181.47 cm

	 18: Distance = 182.35 cm

	 19: Distance = 181.49 cm

	 20: Distance = 181.06 cm

	>> PRU Disabled.

### Reference material:

- [HC-SR04 manual and datasheet](http://www.cytron.com.my/viewProduct.php?pcode=SN-HC-SR04&name=Ultrasonic%20Ranging%20Module)

- [TI PRU docs](http://processors.wiki.ti.com/index.php/Programmable_Realtime_Unit_Software_Development)

- [Introduction to the BeagleBone Black Device Tree](https://learn.adafruit.com/introduction-to-the-beaglebone-black-device-tree/overview)

- [Using a Beaglebone with an HC-SR04 sonar](http://teknoman117.wordpress.com/2013/04/30/using-a-beaglebone-with-an-hc-sr04-sonar/)