TFT LCD DISPLAY EC11 piggy back BOARD

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While browsing the internet, I came across this “TFT LCD Display EC11” board. It is a 2.4-inch color display with a rotary encoder and an additional push button. It’s a nice little board, but you need 12 connections to use the display, rotary encoder, and push button.

This project is sponsered by

Inspired by the “Cheap Yellow Display” board that I used in an earlier project, I thought it would be interesting to design a piggy-back board for this display so it can be used in the same easy way as the Cheap Yellow Display.

This way, the maker only has to come up with a fun application and write the software for it, without having to worry about all the hardware connections.
Possible applications could include:

• Internet Radio
• Universal Timer
• Smart Home Dashboard
• Audio Spectrum Analyzer
• Dashboard for ESPHome or Home Assistant

To allow external modules, such as sensors, to be connected, the board includes an I2C port (3.3V) and a more universal connector with one GPIO output (GPIO27), two input pins (GPIO34 and GPIO35), 3.3V, GND, and — via a solder bridge — 5V.

In hindsight, I should also have exposed GPIO19, but that will be included in the next PCB revision.

In the first revision of this board, I used a CP2104 as the USB-to-UART bridge. However, this chip is so small (QFN package) that it is difficult for the average maker to solder by hand. For revision 2, I switched to the much more manageable CH340C bridge (SOIC-16 package).

All remaining components are small, but still easy enough to solder by hand.

Schematic

One thing that differs from most of my other ESP8266 and ESP32 projects is that I decided to use a USB-to-UART bridge for programming the SoC. Since USB-C has become the new standard, I decided to use that as well. That is why the two 5k1 resistors (R4 and R5) are included. These are used to negotiate the required voltage with the USB hub or computer (5 volts in this case).
I selected a 16 pin Through Hole (THT) connector (USB4085-GF-A)

U1 is an MCP1826S (LDO) capable of delivering up to 1 ampere. However, if you do not have one available, you can also use an LM2937-3.3V or a TC1262-3.3V, since they share the same pinout but provide a lower maximum current (500mA).

U2 is an ESD protection chip that protects the circuit against large voltage spikes. You can safely omit U2, but in that case you must bridge JP1 and JP2 with solder.

SW1 (and R2) and SW2 (and R3) are also not strictly required. If you install them on the board, you can manually reset the SoC or put it into flash mode.

Using a solder bridge, J2 pin 1 can be connected to VBUS. This allows you to either supply 5 volts from the board to an external system or power the board itself from a system connected to J2.

The external connectors J2 and J3 use a 2.50mm pin pitch. You can choose whatever connector type you prefer. I selected JST-XH connectors because they are relatively compact and the female connectors can easily be assembled by hand. However, you could also use screw terminals or simply solder wires directly to the PCB.

Apart from that, the schematic is fairly straightforward.

After designing the PCB in KiCad, I sent the design to for manufacturing.

KiCad includes a very convenient add-on that allows this entire process to be completed automatically with a single button press.

I like working with because they really understand what makers need. Whenever I design a new ESP32 project, custom PCB, or hardware prototype, I mainly care about two things: high quality and fast delivery. And that’s exactly where stands out for me.

The PCB quality has consistently been excellent. Clean silkscreen printing, neat solder masks, and professionally finished boards — even for small prototype orders. That gives me confidence when testing new designs or sharing projects online.

What I personally appreciate most is the speed. In many cases, I receive my PCBs within just a few days. That allows me to iterate faster, fix issues quickly, and keep building without long delays.

For my own projects, has become my go-to PCB manufacturer!

Before ordering the PCB, the only remaining choices are the PCB thickness, the PCB color, and the silkscreen color. Because the through-hole USB-C connector has very short pins, I decided to use a 1mm PCB instead of the standard 1.6mm thickness.

Bill of Materials

	Value	Footprint	Remark
C3, C4, C5, C6	100nF	C_1206_3216_HandSolder
C1	1uF	CP_EIA-3216-12_Kemet-S_HandSolder
C2	10uF	CP_EIA-7343-31_Kemet-D_HandSolder
U3	ESP32-WROVER-E-N4R8	ESP32-WROVER-B-E
J1	USB_C_Receptacle_USB2.0_16P	GCT_USB4085
J3	I2C	JST_XH_B4B-XH-AM_1x04_P2.50mm_Vertical
J2	Control	JST_XH_B6B-XH-AM_1x06_P2.50mm_Vertical
D1	3v3	LED_1206_3216Metric_Pad1.42x1.75mm_HandSolder
J4	TFT-LCD-DISPLAY-EC11	PinHeader_1x12_P2.54mm_Vertical
*R2, R3	220R	R_1206_3216Metric	optional
R4, R5	5k1	R_1206_3216Metric
R6, R7, R8, R9, R10, R11	10k	R_1206_3216Metric
R1	2k	R_1206_3216Metric_Pad1.30x1.75mm_HandSolder
U4	CH340C	SOIC-16_3.9x9.9mm_P1.27mm
Q1, Q2	BC848	SOT-23
*U2	USBLC6-2SC6	SOT-23-6	optional
U1	MCP1826S	SOT-223-3_TabPin2
*SW1	BOOT	SW_SPST_FSMSM	optional
*SW2	EN	SW_SPST_FSMSM	optional