Leguizard PCB

Controlador Motores Brushless

y sensores

Features:
● ESP32 Wroom 1 N8R8 CPU
● 4 ESC Outputs
● 4 Line detecting sensor Inputs
● 9 I²C connectors
● 6 I²C channels design for
LASER module
● 2 SPI outputs
● SD card reader
● 4 GPIO connectors
● 2 UART connectors
● USB programable

Description:
This board is designed to drive a fully autonomous brushless powered robot. The board was designed to
fulfill most needs that any autonomous robot might need. It has the usual ports that any robot might need,
I²C, SPI, UART and GPIO. The board can be powered by two means, by a dedicated BEC or by the
integrated regulator that the ESC has. To regulate the power the board counts with two options, a
NCP1117DT33T5G or a LD1117, both can be disabled with a soldered jumper. Uploading code to the
ESP32 can be done by three different ways,OTA, USB and UART.

1
 Leguizard PCB
Controlador Motores Brushless
y sensores

Pin description:
The chart indicates every pin function and, in the most right column, the use we assign them.
Pin N Name Type Function Use
1 GND P GND GND
2 3V3 P Power supply 3.3v
High: on, enables the chip. Low: off, the chip powers off. Note: Do
3 EN I not leave the EN pin floating. EN
4 IO4 I/O/T RTC_GPIO4, GPIO4, TOUCH4, ADC1_CH3 Q1
5 IO5 I/O/T RTC_GPIO5, GPIO5, TOUCH5, ADC1_CH4 Q3
6 IO6 I/O/T RTC_GPIO6, GPIO6, TOUCH6, ADC1_CH5 GPIOP1
7 IO7 I/O/T RTC_GPIO7, GPIO7, TOUCH7, ADC1_CH6 GPIOP2
8 IO15 I/O/T RTC_GPIO15, GPIO15, U0RTS, ADC2_CH4, XTAL_32K_P GPIOP3
9 IO16 I/O/T RTC_GPIO16, GPIO16, U0CTS, ADC2_CH5, XTAL_32K_N GPIOP4
10 IO17 I/O/T RTC_GPIO17, GPIO17, U1TXD, ADC2_CH6 GPIOP5
11 IO18 I/O/T RTC_GPIO18, GPIO18, U1RXD, ADC2_CH7, CLK_OUT3 GPIOP6
12 IO8 I/O/T RTC_GPIO8, GPIO8, TOUCH8, ADC1_CH7, SUBSPICS1 GPIOP7
RTC_GPIO19, GPIO19, U1RTS, ADC2_CH8, CLK_OUT2,
13 IO19 I/O/T USB_D- USB -
RTC_GPIO20, GPIO20, U1CTS, ADC2_CH9, CLK_OUT1,
14 IO20 I/O/T USB_D+ USB +
15 IO3 I/O/T RTC_GPIO3, GPIO3, TOUCH3, ADC1_CH2
16 IO46 I/O/T GPIO46 GND
RTC_GPIO9, GPIO9, TOUCH9, ADC1_CH8, FSPIHD,
17 IO9 I/O/T SUBSPIHD M1-PWM
RTC_GPIO10, GPIO10, TOUCH10, ADC1_CH9, FSPICS0,
18 IO10 I/O/T FSPIIO4, SUBSPICS0 M1-C
RTC_GPIO11, GPIO11, TOUCH11, ADC2_CH0, FSPID, FSPIIO5,
19 IO11 I/O/T SUBSPID B1
RTC_GPIO12, GPIO12, TOUCH12, ADC2_CH1, FSPICLK,
20 IO12 I/O/T FSPIIO6, SUBSPICLK B2
RTC_GPIO13, GPIO13, TOUCH13, ADC2_CH2, FSPIQ,
21 IO13 I/O/T FSPIIO7, SUBSPIQ POWER-I

2
 Leguizard PCB
Controlador Motores Brushless
y sensores

RTC_GPIO14, GPIO14, TOUCH14, ADC2_CH3, FSPIWP, POWER-

22 IO14 I/O/T FSPIDQS, SUBSPIWP V
23 IO21 I/O/T RTC_GPIO21, GPIO21 M2-C
24 IO47 I/O/T SPICLK_P_DIFF,GPIO47, SUBSPICLK_P_DIFF M2-PWM
25 IO48 I/O/T SPICLK_N_DIFF,GPIO48, SUBSPICLK_N_DIFF M3-C
26 IO45 I/O/T GPIO45 M3-PWM
27 IO0 I/O/T RTC_GPIO0, GPIO0
28 IO35 I/O/T SPIIO6, GPIO35, FSPID, SUBSPID SCL [I2C]
29 IO36 I/O/T SPIIO7, GPIO36, FSPICLK, SUBSPICLK SDA [I2C]
30 IO37 I/O/T SPIDQS, GPIO37, FSPIQ, SUBSPIQ SS1
31 IO38 I/O/T GPIO38, FSPIWP, SUBSPIWP M4-C
32 IO39 I/O/T MTCK, GPIO39, CLK_OUT3, SUBSPICS1 M4-PWM
33 IO40 I/O/T MTDO, GPIO40, CLK_OUT2 SCK
34 IO41 I/O/T MTDI, GPIO41, CLK_OUT1 MOSI
35 IO42 I/O/T MTMS, GPIO42 MISO
36 RXD0 I/O/T U0RXD, GPIO44, CLK_OUT2 RDX
37 TXD0 I/O/T U0TXD, GPIO43, CLK_OUT1 TDX
38 IO2 I/O/T RTC_GPIO2, GPIO2, TOUCH2, ADC1_CH1 Q2
39 IO1 I/O/T RTC_GPIO1, GPIO1, TOUCH1, ADC1_CH0 Q4
40 GND P GND GND
41 EPAD P GND GND

In yellow are pins that have specific functions during the boot and reboot process. Pin 3, Enable, Reboots
the ESP, while the pin 27, IO0, Is used for booting a new program into the chip.

In red are pins that configure the Chip Boot Mode Control.1

1
To know more about these pins read section 3.3.1 of the ESP32 datasheet.

3
 Leguizard PCB
Controlador Motores Brushless
y sensores

Connectors diagram:
The board counts with 33 connectors, each designed with a purpose in mind. The terminals can be
subdivided in 8 big groups, between those groups the connector pitch changes making it impossible to
mix up the wiring. Anding to that, each connector has a clear silkscreen name indicating the function that
it complies with.

Motors:
This group is formed by four JST XH B4B connectors in each corner of the board. The identifiers are M1,
M2, M3 and M4. Every connector has in common three signals, GND, Motor PWM and Motor Direction.
Additionally each terminal has one more pin, the pin N1, that is of no use in three out of four connectors,
only in M1 it serves the function of Auxiliary BEC. This is because most Electronic Speed
Controllers(ESCs) have one in them supplying 5v. These functions can be toggled on and off2.

Line detecting sensors:

This group is formed by four JST XH B3B connectors in each corner of the board. The identifiers are
QTR-1, QTR-2, QTR-3 and QTR-4. Every connector has two signals in common, Vcc and GND. The
third pin corresponds to an analog input.

2
see Jumpers section.

4
 Leguizard PCB
Controlador Motores Brushless
y sensores

Current and Voltage measurements:

This group is formed by four JST XH B2B connectors in each corner of the board. The identifiers are V &
I. Every connector has two analog inputs that measure the voltage and current that flows to each ESC.

Inter-Integrated Circuit(I²C):
This group is formed by three JST XH B4B and six JST PH B5B connectors placed in a row. The
identifiers are LASER and I2C. Every terminal shares three signals, GND, SDA and SCL. In the one hand
the JST XH B4B (I2C), have in the fourth pin a Vcc connection, which can be 3.3v and 5v according to
the jumpers configuration3. On the other hand the JST PH B5B has a 5v non configurable source and a
fifth pin which goes to a digital IO pin. This pin is for the XShut pin on most LASER modules.

Serial Peripheral Interface(SPI):

This group is formed by two JST XH B6B placed side by side. The identifier is SPI. Each connector has
five pins in common, GND, configurable Vcc4, MOSI, MISO and SCK. The sixth pin corresponds to the
Slave Select(SS) that goes to a digital IO pin.

Universal Asynchronous Receiver Transmitter(UART):

This group is formed by two JST PH B4B and one four pin Male Header placed in a row. The identifier
for the group is Serial. Every terminal has the same connection, GND, 5v, Rx and Tx. The header is
meant only for special cases where OTA and USB methodes for programming the chip didn’t work. In
those cases there is the option to solder the header and upload code via an ST-Link stick.

General Inputs & Outputs(GPIO):

This group is formed by three JST ZR B3B and one JST ZR B6B In a row. The group identifier is GPIO.
In the one hand the JST ZR B3B connectors have two pins in common, GND and a configurable Vcc5, the
third pin is connected to an analog Input. On the other hand the JST ZR B6B connector has GND, a
configurable Vcc and four analog inputs.

3
See Jumper section for more info.
4
See Jumper section for more info.
5
See jumper section.

5
 Leguizard PCB
Controlador Motores Brushless
y sensores

Miscellaneous connectors:
This group is formed by one JST ZR B4B and one two pin male header. The JST ZR B4B connector is
identified as USB and the male header is identified as Aux. The JST ZR B4B is connected to the D+ and
D- of the Esp32 while the Aux header is connected to the 3.3v net via an NC switch. This allows you to
toggle on only the esp32 without turning on the other circuitry.

Power:
This group is formed by one JST XH B6B. The JST XH B6B connector is identified as BEC. It has two
GND pins, two togable Vcc pins, a current and a voltage sensing pin. This BEC is intended to power the
board and measure the battery voltage and current.

Jumpers:
The board counts with a jumper system to give more freedom while choosing sensor options. This
consists of three main systems, the address system, the voltage system and the enable system. The address
system allows you to change the address of the IO expander, the voltage system allows you to connect 5v
sensors or 3.3v sensors, offering a wider range of options, and the enable system allows you to choose the
power source, BEC or ESC BEC. To set either option you have to solder a jumper in the designated area
shown in the table below.

6
 Leguizard PCB
Controlador Motores Brushless
y sensores

Connector 3.3v Jumper designator 5v Jumper designator

J22 W27 W24
J23 W28 W25
J24 W29 W26
CON1 W23 W14
J20 W11 W9
J19 W10 W2
J6 W7 W8
J4 W5 W6
J1 W3 W4

Designator Enable pins

J11 W30 & W31
J10 W22 & W42
U10 W13

MPC23017
Pin Number GND 5v
1 W20 W17
2 W19 W16
3 W18 W15

The solder jumper must be done over the line that joins the footprint, as shown:

Correct way Incorrect way

IT IS IMPORTANT NOT TO SOLDER MORE THAN ONE JUMPER PER CONNECTION, that will
cause a short circuit. It is also mandatory to solder all jumpers on the address system, if not it could cause
problems while assigning devices.

7
 Leguizard PCB
Controlador Motores Brushless
y sensores

SD slot:
The board counts with an SD slot for data logging. To write to the Sd card the SPI protocol is used, the
SS(Slave Select) pin is located on pin 30 of the ESP32.

Bill Of Materials:
Name Designator Quantity Manufacturer
APHCM2012SYCK-F01 D1 1 Kingbright
B3B-ZR(LF)(SN) J7, J8, J9 3 JST
B4B-XH-A(LF)(SN) J10 → J12, J21 → J24 7 JST
B4B-ZR(LF)(SN) J6 1 JST
B6B-PH-K-K(LF)(SN) J1 1 JST
B6B-XH-A(LF)(SN) J19, J20 2 JST
CRCW080510K0FKEA R1, R6, R8, R9, R12 5 Vishay
CRCW080547K0FKEA R3, R5 2 Vishay
CRCW0805390RFKEA R10, R11 2 Vishay
ERJ-P06F1001V R13 → R21, R27, R28, R33 12 Panasonic
GRM31CR71A226KE15L C6, C7 2 Murata
LTST-C170KFKT D13 1 Vishay Lite-On
NCP1117DT33T5G U7 1 ON Semiconductor
RG2012N-332-C-T5 R22, R23, R24, R25 4 Susumu
SN74LVC125APWR U9 1 Texas Instruments
TMK212BBJ106KG-T C1 1 Taiyo Yuden
TXS0108EQPWRQ1 U5, U6 2 Texas Instruments
B6B-ZR CON1 1 JST
ESP32-S3-WROOM-1
N8R8 U1 1 Expressif systems
Header 2 P1 1 -

8
 Leguizard PCB
Controlador Motores Brushless
y sensores

Header 4 P6 1 -
Jumper W1 → W29 29 -
Test point T1, T2, T3 3 -
TS10-63-26-BE-250-SMT-
TR S1 1 CUI Devices
150080BS75000 D4 → D20 16 Wurth Electronics
150080SS75000 D3 1 Wurth Electronics
473521001 SD1 1 Molex
ADS1115IDGST U3, U4 2 Texas Instruments
B2B-PH-K-S(LF)(SN) J2, J3, J4, J5 4 JST
B3B-PH-K-S(LF)(SN) P2, P3, P4, P5 4 JST
B4B-PH-K-S(LF)(SN) P7, P8 2 JST
B5B-PH-K-S(LF)(SN) J13, J14, J15, J16, J17, J18 6 JST
BAS3010A03WE6327HTS
A1 D2 1 Infineon
C0805C105K4PACTU C3 1 KEMET
CRCW0805680RFKEA R7 1 Vishay
ERJ6ENF6800V R26 1 Panasonic
ERJ-6ENF1500V R29, R30, R31, R32 4 Panasonic
FSMSMTR SW1, SW2, SW3, SW4 4 TE Connectivity
GRM21BR71H104KA01L C2, C4, C5 3 Murata
HSMG-C170 DS1, DS2 2 Broadcom Avago
LM7805CT U8 1 ON Semiconductor / Fairchild
PCF8574DWR U2 1 Texas Instruments
RC0805FR-07100KL R2, R4 2 Yageo

Any → indicates that the sequence goes from the first designator adding one to the last designator.
Eg: R1 → R4 = R1,R2,R3,R4

The complete BOM is attached to the project.

9
 Leguizard PCB
Controlador Motores Brushless
y sensores

Physical dimensions:

The Mounting holes present are M2 HEX.

Programing the ESP32:

Programing the ESP32

1. Install Arduino IDE6

2. Download & install the ESP family boards7
3. Download & install the libraries
4. Upload the code to the board

There are several ways you can upload the code to the ESP32.

● Via OTA programing8

● Via USB port
● Via TTL protocol (use only when the other two methods didn’t work)
6
See resources section for more info about Arduino
7
See resources section for more info about the ESP family
8
See resources section for more info about OTA programing

10
 Leguizard PCB
Controlador Motores Brushless
y sensores

To have access to Tx & Rx pins, for the TTL programing, there is an unsoldered header in the Serial
section of the board. To Upload the code you must have an ST-LINK.

BE AWARE THAT THE CODE WON’T BE UPLOADED IF YOU DON'T PRESS THE BOOT
BUTTON. If the code still doesn't uploads correctly you can try to supply the board with 3.3v ONLY
externally and disconnect the rest of the circuit via the Chip PWR button. The connector to supply the
board is identified as Aux.

Considerations:
Knowing the environment that the board will probably be used, here we list a few recommendations:

● Installing the board near brushless motors will inevitably cause electrical noise. We recommend
shielding as best as possible the motors, the wires, and if possible the board.

● Installing the board in a mechanical stressful place will cause internal stresses in the board, in the
solder joints and in the internal connections of the components. We recommend that if there are
any problems with stability you change the board or at least reflow the PCB.

● Installing the board in an enclosed area can cause problems with the OTA, WiFi and BlueTooth
wireless communications. This holds especially true if the casing is conductive.

● The GPIO pins, available on the board, can be used to source up to 28mA MAX without
irreversibly burning the ESP32.

● We do not recommend installing the board in a environment that exceeds the 50॰ C.

Resources:
● ESP32 wroom 1U N8R8 datasheet
● ESP32 family
● Arduino
● Over The Air programing
● GitHub Repository

11