How do I use my DC Step-up Converter to get 5V out of a LiPo?

Hardware
1

My HC-SR04 has a 5V working voltage and 15mA, working current, but my LiPo only delivers 3.7V. I bought a DC Step-up with an input voltage of 0.5 to 5.5V and maximum input current of 1.2A.

Here’s my setup:

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GND to GND, VIN to VCC, D2 to Echo and D5 to Trig. I want to use a DC Boost (Polulu U1V10F5) for this, but I’m not sure how the wiring goes (Looked at some explanations, tried out some stuff but at this point afraid to make a mistake and screw up my sensor). DC Boost has a Vin, Vout and GND pin.

My guess would be that 3V3 goes to VIN (DC), VOUT (DC) goes to VCC (HC-SR04) , but then what about the GND?

2

GND goes to GND - this is what we call common ground.
All GND pins need to have to be tied together (unless you are going for galvanic isolation).

3

Right, thats what I thought; I tried wiring both the GND from the Electron and the sensor to the DC Stepup GND (in two adjacent pins in the same row) but it didnt work for me. I’ll try it again after the weekend and see if i can figure out whats wrong

4

If you draw up your wiring diagram and post that here things will be easier to see and talk about.

2 Likes
5

here’s an image. 3V3 to VIN. VOUT to VCC of the HC-SR04. And then the GND from both the DC Step-up and HC-SR04 to a power rail, connecting them to GND on the Electron.

I tried some other setups as well such as leaving some wires out or going directly from HC-SR04 to the Electron but nothing works. Sometimes it does give me a couple of readings, which are all over the place.

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Just for the record:
DC Step has the pins VIN, GND, VOUT (from top to bottom)
HC-SR04 has the pins GND, Echo, Trig, VCC (from top to bottom)

6

@Vitesze, you need to solder the wires to the Polulu board! Dude!

2 Likes
7

To be more specific you need to solder the header pins to the converter board.

If you running less than 2 amps the jumper wires should work without to much voltage drop.

1 Like
8

Thanks for the reply. Will try this tomorrow, see how it goes :smiley:

9

I’m happy to tell you that I used jumper wires instead and the sensor seems to work fine now :slight_smile: Although I will consider them soldering later on.