Simply Automationized

Thursday, October 22, 2015

20+ Ultrasonic Distance Sensors Compared

Since there are many uses for ultrasonic sensors (Robots, Liquid Level Sensor, Motion Sensor, Vehicle Parking/Backup, on and on....) I compiled a list of 20+ sensors with their min/max ranges along with precision and how it interfaces with your RPi or Arduino. Prices Ranging from ~$2 usd to nearly $175+ usd. You can connect several to your project with all of these sensors.

Sensor	Min Range	Max Range	Freq.	Precision	Interface	Price (usd)
SRF08	3cm	6m	?	3-4cm	I2c	$50
SRF10	6cm	6m	40 KHz	?	I2c	$33
SRF02	15cm	6m	40 KHz	?	I2c/UART	$14
SRF04	3cm	3m	40 KHz	?	Pulse	$22
SRF05	1cm	4m	40 KHz	?	Pulse	$22
MaxSonar-EZ Series	15cm	6.45m	42 KHz	2.54cm	PWM / Serial / Analog / I2c	$25-$40
ProxSonar-EZ Series	3cm	3m	42 KHz	2.54cm	USB / Serial / Digital Logic	$50
SRF01	0cm	6m	40 KHz	3-4cm	UART	$28
SRF235	10cm	1.2m	235 KHz	3-4cm	I2c	$109
URM04	4cm	5m	40 KHz	1cm	RS485	$26
URM06	20cm	10m	49.5 KHz	1cm	Analog	$59
MaxSonar-WR Series	30cm	10m	42 KHz	.1cm (1mm)	PWM / Serial / Analog / I2c	$99-$175
ParkSonar-EZ Series	15cm	1.84m - 3.66m	42 KHz	2.54cm	PWM / Serial / Analog / I2c	$30
MaxSonar-AE Series	1mm	7m	42 KHz	1cm	Serial / Analog / I2c	$40-$55
US-100	2cm	4.5m	40 KHz	0.3cm	Pulse / UART	$4
US-020	2cm	7m	40 KHz	0.3cm	Pulse	$5
US-015	2cm	4m	40 KHz	3cm	Pulse	$4
HC-SR04	2cm	4m	40 KHz	3cm	Pulse	$3
HY-SRF05 / HC-SR05	2cm	4.5m	40 KHz	0.2cm	Pulse	$2
DYP-ME007Y	30cm	3m	40 KHz	1cm	Pulse	$13
Parallax PING)))	2cm	3m	40 Khz	?	Pulse	$30
URM37	2cm	5m	?	1cm	PWM / UART	$14

Sunday, October 11, 2015

Raspberry Pi Temperature Sensors Compared

Before we start lets first name off the different ways to interface things to your raspberry pi. I2c, SPI, UART, digital pins, usb (which will be one of the previous serial protocols just converted to USB), and ethernet (same as usb serial with some MCU with an ethernet interface). If the raspberry pi had an ADC I would've included some of them. If you want to use an analog sensor you'd need to find an ADC --> I2c/SPI board/module.

This list I will update as I find more:

Sensor	Temperature Low	Temperature High	Precision	Interface	Price (usd)
DS18B20	-55°C (-67°F)	125°C (257°F)	0.0625°C (0.11°F)	Dallas 1-Wire	$2
DHT11	0°C (32°F)	50°C (122°F)	1°C (3.3°F)	1-wire	$5
DHT22/AM2302	-40°C (-40°F)	80°C (176°F)	0.1°F (0.18°F)	1-wire	$5
AM2312	-40°C (-40°F)	80°C (176°F)	0.1°C (0.18°F)	I2c	$15
MCP9808	-40°C (-40°F)	125°C (257°F)	0.0625°C (0.11°F)	I2c	$5

DS18B20

East of Setup: Medium

Temperature Range: -55°C to +125°C (-67°F to +257°F)

Interface: Digital 1-Wire

Benefits: Can daisy chain many of them along the same serial bus.

Limitation: Requires a 4.7k resistor. The communication is slow (about 1 second per sensor) which can slow down how often you're getting updates if you have 10+ on the bus. For I2c/UART (need interface board for I2c/UART)

Price: $2

Links For Setup: Adafruit Tutorial, ModMiPi Tutorial,
Some Python Libraries: Github

DHT11 / DHT22 / AM2302

I put these three together because of their similarities. The AM2302 / DHT 22 have a higher and lower temperature range. Each type requires a 10k resistor per sensor.

Temperature Range: AM2302/DHT22 -40°C to +80°C (-40°F to +176°F)

Temperature Range: DHT11 0°C to +50°C (32°F to +122°F)

Interface: Digital 1-wire (not same as Dallas 1-Wire protocol)

Benefits: Senses humidity. DHT11 isn't too expensive

Limitations: DHT11 has a limited temperature range. Not waterproof unless you buy an encapsulated version, which will not sense humidity as well.

Price: DHT11 ~$5, AM2302 / DHT22 ~$6-$20

Links For Setup: Adafruit

Some Python Libraries: Github Adafruit

AM2321

Since this sensor uses I2c I separated it from the above AM2302/DHT22. Requires pull-up resistor 3l-10k.

Temperature Range: -40°C to 80°C (-40°F to +176°F)

Interface: I2C

Benefits: Senses humidity.

Price: $15

Links: Datasheet Python

MCP9808

Temperature Range: -55°C to +125°C (-67°F to +257°F)

Interface: I2c

Benefits: Can connect up to 8 different modules. High precision .0625°C

Price: $2

Links For Setup: Adafruit Tutorial
Some Python Libraries: Github

Other ones to look into:

BMP180

Barometric Pressure Sensor I2c, which has temperature sensing abilities. $7

MPL115A2 Adafruit's barometric Pressure Sensor I2c includes temperature sensing, $15

LM75

I2c Temperature sensor -25°C~100°C.

Interesting and possibly helpful one for your robot:

US-100 Ultrasonic sensor with UART interface $5. (UART commands)

Monday, September 28, 2015

List of 18 Crowdfunded Raspberry Pi Boards That Didn't Make It

If you're looking to crowdfund your Raspberry Pi project maybe you can learn what didn't go right for these projects. Here is a list of hardware projects that didn't get funded. This list was pulled from the two top crowdfunding sites Indiegogo and Kickstarter. This isn't all of the projects that I had found but some of the more interesting ones.

*Note items in the list may have been re-listed later and funded. Some projects may have been ahead of their time as the Pi wasn't popular enough.

Img	Project	Descripton	Backers	Pledge / Goal / %
Img	Project	Descripton	Backers	+1 Button
	CoMo Booster	Board for Rpi Module with: wifi, oled screen, digital audio, RTC, 6-36v power input.	55	$6,834 / $40,000 / %17
	ZIR EL-200	"ZIR EL-200 is connected to your computer, smartphone or tablet using Wi-Fi wireless network, and from there we set or directly assign instructions using the browser. However, one of its most interesting features is the ability to also be controlled by voice, using for that purpose applications on iOS and Android."	60	$5,012 / $90,000 / %5.6
	1080Pi	10" 1080p Screen that mounts to the Rpi GPIO with 16 extra GPIO, 4 with 3A sinking current.	189	£20,451 / £100,000 / 20%
	RFberryPi	A 433Mhz Radio Shield used to communication with several peripherals such as relays & sensors.	14	£321 / £4,850 / 6.6%

	SerialPi5	Board giving the Rpi the ability to have 5 RS-232 serial ports.	5	£261 / £11,000 / 2%
	Jilia Iot Dev Kit	"Add ZigBee, Z-Wave, Bluetooth, and Wi-Fi to your Raspberry Pi with on-board sensors and an easy cloud API."	119	$6,256 / $50,000 / 12.5%
	RF Breakout Kit	Breakout kit to build your own radio using the Rpi's built in clock generator. Frequencies up to 250Mhz	126	£1,330 / £1,800 / 72%
	Bridge Shield	Bridge an Arduino with: RTC, Motor drivers, Temp Sensor, IR Sensor, USB-UART converter, 5V 3A Reg, header for ESP8266, header for HC-05, level shifting between Rpi and Arduino, 8 Servo Motor Driver (I2C)	45	$2,696 / $4,100 / 65.8%
	Pi UpTime	"GPIO connections, analog ports, UPS, RTC & battery power enabling Raspberry Pi to be mobile." 17 hours of uptime on full battery, 2 analog input, RTC, and	25	$4,020 / $15,000 / 26.8%

	Hatlogico	"Open-source 16 PWMs, 8 ADCs and dual-voltage communications to sit on your Raspberry Pi to drive your quadcopter, robot, 3D printer etc"	42	£1,352 / £4,800 / 48.3%
	BattPi	"BattPi is a Case for Raspberry Pi with integrated Battery and Real Time Clock. Built in UPS offering up to 8 hours of battery life."	34	£1,973 / £20,000 / 9.9%
	ProtoPLC	Industrial add-on board. 6 inputs, 6 outputs, 1 analog input, 1 analog output, programmable leds.	28	$3,653 / $20,000 / 18.3%
	Raspitab	Hackable tablet built from the Rpi Module with 3400mah battery, 7" screen, wifi usb, 5MP camera module.	87	£9,981 / £125,000 / 8%
	Pi-Home	Add-on board with the ability to control: Zwave, Infra-red devices (TV/DVD..), RF Device (315/433 Mhz Plugs), and Zigbee devices.	80	$10,001 / $15,000 / 66.7%

	TX-1	GSM Cellular phone w/GPS add-on module.	5	$641 / $14,000 / 4.6%
	HDMI Input Module	"Add an HDMI input interface to your Raspberry Pi and record or stream high quality video from your HD camcorder with clean HDMI output."	63	$6,907 / $15,000 / 34.5%
	easyPio	GPIO breakout module for prototyping.	45	£329 / £1,200 / 27%
	RasPoE	Raspberry Pi PoE Shield.	28	€3,310 / €12,500 / 26.5%