Quad Stall Motor Control and Sense board for ESP32, bare circuit board w/ doc

$15.00

This is a circuit board to for an add-on board for a Pocket Beagle that will control four stall-motor turnout motors for a model railroad. It also has sense logic to return the state of the turnouts, using one pole of the DPDT contacts in the stall-motor (typical of Tortoise stall-motors).

3 in stock

Description

This is a circuit board to for an add-on board for a Pocket Beagle that will control four stall-motor turnout motors for a model railroad. It also has sense logic to return the state of the turnouts, using one pole of the DPDT contacts in the stall-motor (typical of Tortoise stall-motors).

Project Page on GitHub

GPIO Pins Used.

This board uses eight GPIO pins:

GPIO0:
Motor Select 1: select the position of stall motor 1.
GPIO12:
Motor Select 2: select the position of stall motor 2.
GPIO34:
Point Sense 1: return the state of the points for stall motor 1.
GPIO35:
Point Sense 2: return the state of the points for stall motor 2.
GPIO15:
Motor Select 3: select the position of stall motor 3.
GPIO25:
Motor Select 4: select the position of stall motor 4.
GPIO32:
Point Sense 3: return the state of the points for stall motor 3.
GPIO33:
Point Sense 4: return the state of the points for stall motor 4.

Each of the motor drive circuits is through a TC4428, which can drive up to 1.5A, which is way more needed to drive typical stall motor. It is enough to drive a pair of stall motors, wired in parallel as would be the case for a cross over.

Circuit Description

This circuit contains two sections. There is an output section that contains four TC4428 chips. Each chip has a non-inverting and an inverting driver. The inputs of both drivers are connected to one of the motor GPIO pins. The output are wired to the terminal block for a one of the motors. For any given logic state of the motor control output, one of the drivers is “on” and the other is “off”, thus one motor terminal is ground and one is raised to the 12V supply. This means alternative states of the logic line will drive the stall motor in alternative directions.

The other section is a quartet of flip-flop debounce circuits, one for each of two SPDT switch contacts that report the position of the turnout points. The output of these flip-flops goes to a quartet of GPIO input pins.

Parts List

Value Quantity References Mouser Part Number
.1 uf 2 C1 C2 581-SR201C104KARTR1
10 uf 35V 1 C3 667-ECA-1HM100I
18 Pin socket header 1 U0 517-929850-01-18-10
19 Pin socket header 2 U0 517-929974-01-19-RK
10K Ohms 1 RR1 652-4609X-1LF-10K
Motor 1;Motor 2;Motor 3;Motor 4 4 T1 T2 T3 T4 651-1725685
+ 12V – 1 T5 651-1725656
TC4428 4 U1 U2 U3 U4 579-TC4428VPA
74HCT00 2 U5 U6 595-SN74AHC00N
.1 uf 1 C1 21RZ310-RC
15 uf 63V 1 C2 710-860080773002
47 nf 1 C3 75-1C10Z5U473M050B
SB240E 2 D1 D2 625-SB240-E3
RJ45 2 J1 J2 710-615008144221
Termination 1 JP1 649-67997-404HLF
60 Ohms 2 R1 R2 71-RN60C60R0B/R
+ 15 in -;+ 15 out – 2 T1 T2 651-1725656
TCAN332DR 1 U1 595-TCAN332DR
SN65HVD233-HT 1 U2 595-SN65HVD233SJD
220 uf 25V 1 C4 140-REA221M1EBK0811P
22 uf 100V 1 C5 140-REA220M2ABK0811P
SB160-E3/54 1 D3 625-SB160-E3
330 uh 1 L1 PE-52627NL
LM2574N-5.0 1 U3 926-LM2574N-5.0/NOPB
Value Quantity References Mouser Part Number

The only parts that might be substituted are T1 though T4 (the Motor
terminals) and T5 (the 12 to 16 Volts terminals). The parts listed are for
screw terminals for the Motor terminals and the motor power terminals. Feel
free to select either pin arrays or spring terminals for the T1, T2, T3, T4
and T5. You only need one CAN transciever. One of the parts is a through hole
version (which is much more expensive) and the other is SMD. The SMD part can
be hand soldered. The board supports using either a pair a 18-pin headers for
a TTGO-T1 MCU board or a pair a 19-pin headers for a ESP32 Dev Kit Board.

Circuit Board Layout

Board assembly is straight forward. You need to be careful orienting the ICs and the electrolytic capacitor.

Additional information

Brand

The Country Robot

Function

Point Sense, Stall Motor Driver

Interface

LCC CAN

MCU/SMB

ESP32