HardLabs

Scale hx711

IoTReady·low-power-nrf52-weighing-scale·design/scale_hx711/scale_hx711.kicad_pcb

Scale hx711 PCB layout, top view — open source Nordic nRF board by IoTReady
Simulate this board

About the Scale hx711 PCB

Scale hx711 is an open source Nordic nRF PCB design by IoTReady, published on GitHub. It is a 2-layer board measuring 70 × 40 mm, with 75 components from 47 distinct parts.

Its main chip is the MDBT42Q, from the Nordic nRF family. Other key parts include the BQ21040, TPS7A0233PDBV, HX711, LM2703 and LP2985-5.0. By type, the board carries 32 capacitors, 15 resistors, 6 ICs, 5 diodes, 4 transistors and 4 connectors.

It belongs with the iot & wireless designs in this gallery.

From the project

https://iotready.co/low-power-nrf52-weighing-scale/

Here one can find all the Hardware design files. We tried 3 different designs for the weighing scale project and settled with the "HX711" based design as our final. So you will find the final design explained on the main page. The other two designs of "LPV821" and "LTC6915" based weighing scales are also fully functional, one may have to play around with the adc functions in the firmware though.

Main components on the Scale hx711

MDBT42QBQ21040TPS7A0233PDBVHX711LM2703LP2985-5.0

Scale hx711 bill of materials (BOM)

75 components, 47 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
MDBT42Q
U1
1
BQ21040
U2
1
TPS7A0233PDBV
U3
1
HX711
U4
1
LM2703
U5
1
LP2985-5.0
U6
1
IRLML6401
Q1
2
AO3400
Q2, Q4
1
BC857
Q3
1
Q13FC1350000400
Y1
1
USB_B_Micro
J1
1
Conn_02x03_Odd_Even
J2
1
Load cell
J3
1
Conn_01x04
J4
1
Battery_Cell
BT1
1
EINK_GDEW0154M09_154IN_200X200
EINK1
1
SW_SPST
SW1
1
ON/OFF switch
SW2
1
LED
D1
4
SD103AWS
D2, D3, D4, D5
Show 27 more
QtyPartRefs
1
18nH
L1
1
10uH
L2
1
10uH/250mA
L3
1
3.3uH
L4
2
1uF
C1, C3
4
1uF
C2, C7, C8, C9
2
8pF
C4, C6
1
0.1uF
C5
8
1uF/50V
C10, C11, C12, C13, C14, C19, C20, C21
1
10uF
C15
3
0.1nF
C16, C23, C25
3
1uF
C17, C18, C30
3
4.7uF
C22, C29, C32
1
10uF
C24
1
0.1uF
C26
1
100nF
C27
1
4.7pF
C28
1
10nF
C31
2
1.1k
R1, R3
3
10k
R2, R14, R15
1
1M
R4
1
0.47
R5
1
4.7k
R6
1
24k
R7
2
100
R8, R9
2
1.2k
R10, R13
2
3.9k
R11, R12

Scale hx711 design files

The KiCad project lives in the IoTReady/low-power-nrf52-weighing-scale repository on GitHub; these links point at the commit this page was built from.

Scale hx711: common questions

What microcontroller does the Scale hx711 use?

The Scale hx711 is built around the MDBT42Q, from the Nordic nRF family.

How big is the Scale hx711 PCB?

The Scale hx711 measures 70 × 40 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Scale hx711?

75 components, from 47 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.

Where can I download the Scale hx711 design files?

From the IoTReady/low-power-nrf52-weighing-scale repository on GitHub, which has the KiCad layout and the BOM; the links under Design files point to each one.

Can I use the Scale hx711 design in my own project?

The repository has no license, so all rights stay with IoTReady. Use it as a reference, and ask the author before reusing the design.

Can I test firmware for the Scale hx711 without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug Nordic nRF firmware against it before you order a PCB.

More boards in low-power-nrf52-weighing-scale

Similar boards