[PD Charging] Mini Ductless Grip Controller

(1) This project includes:
1. lcEDA pcb project
2. BOM
3. Keil5 C language project
4. HEX file
5. SolidWorks component project
6. STL file
7. In-program display bitmap file
(2) Required components (modules): 1.
29mm 7.4V low-voltage ducted fan
2. Little Bee 30A BlHeli-s 2-6s ESC
3. Circular 5mm long-tail flexible resistive thin-film pressure sensor
4. 0.91-inch OLED display module IIC 12832
5. 18650 battery box with pins on the back
6. Two 18650 power batteries (discharge above 10A)
7. C8051F emulator, etc. (requires a downloader that supports C2 interface)
8. USB to TTL serial port downloader
(3) Physical introduction:

![Screenshot_20240814_151545_com.hihonor.photos.png]
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![IMG_20240814_144743.jpg] (4) Illustrated tutorial:
First, process the ESC. Peel off the heat shrink film of the ESC and remove all connecting wires: Next

, remove the LDO chip, disconnect its 3.3V output from the circuit board, ensure proper insulation, and reinstall it. Use six enameled wires to connect the LDO's 3.3V output, the ESC's S-terminal (PWM input), and the four test points. Make sure you remember which wires are connected correctly. Before reinstalling the power cord

, bend the tinned portion of the wire at a 90° angle to shorten the ESC's length.

[Image 1] The test point definition is shown in the figure.

[Image 2] Wrap the ESC with high-temperature tape and connect it to the motor as shown in the figure. Note that the ESC MOSFET face should face the motor, and the power supply terminal of the ESC should be aligned with the motor's air inlet casing.

[Image 3
] Apply solder paste as shown in the
figure and mount the components according to the BOM. Note the orientation of the chips and diodes, and ensure that the chips are properly soldered before mounting the inductor. The buttons should be soldered with medium-temperature solder (low-temperature soldering is not strong), and the Type-C connector should also have its housing pins reinforced with medium-temperature solder. [

Images 1]
[Images 2] After checking and confirming everything is in order, use a short-pin connector, bend the pins, and solder it to the debugging interface.

[Images 3] Now you can download the program. Use the STC-ISP software:
Set the chip model: STC8H1K08.
Set the serial port (select USB to serial module).
Open the program file: the hex file for this project.
Set the frequency to 30MHz.
Connect the RX and TX pins of the debugging interface: (There is a string of letters next to the debugging interface, GVPKDRT, which stands for GNDV3.3PWMCKCDRXTX).
Click Download/Programming, and then power on the circuit board according to the prompts.
(Once the program is written, you can connect the screen to test it. The four pads next to the debug port are the screen interface. The first pad on the button is GND, and the next three should be soldered in the same order as the screen port. After soldering, connect the V3.3 and GND of the debug port, press and hold the button for three seconds to power on. The screen will light up with the power-on icon, indicating success.)

![capture_20240814161313091.jpg] Next, process the sensor. Use two enameled wires to extend the sensor interface

. ![Screenshot_20240814_170757_com.hihonor.photos.png] Then wrap the sensor head with tape twice to slightly increase its thickness (not too thick! Ensure that the sensor is not compressed when the battery compartments are not squeezed, even when the battery compartments are between them!)
. ![Screenshot_20240814_171040_com.hihonor.photos.png] Then bend one of the pins of each of the two battery compartments at a 90° angle to install the motherboard. (Because the two battery boxes are connected in series, one needs to be bent to positive and the other to negative, as shown in the picture:

![Screenshot_20240814_172052_com.hihonor.photos.png] Secure the sensor in the center of the battery box with tape. Fold the sensor wire as shown in the picture, with the connector perpendicular to the bottom of the battery box at a 90° angle, so that the connector is located in the gap next to the battery box to prevent interference with the pressure sensor.

![Screenshot_20240814_172628_com.hihonor.photos.png] Then solder the two unbent pins of the battery box together, making sure that one is positive and the other is negative. (Ensure a reliable connection!))

![Screenshot_20240814_173423_com.hihonor.photos.png] Thread another enameled wire through one of the gaps, solder it to this point, and lead it out as a battery balancing wire.

![Screenshot_20240814_173615_com.hihonor.photos.png] Lead out one balancing wire and two sensor wires from the pin-side, cover the motherboard (note the positive and negative terminals! The Type-C side is positive!), and then solder the three wires to their corresponding pads. As shown in the image:

![Screenshot_20240814_174702_com.hihonor.photos_edit_1604295557941601.png] Take out the previously processed motor ESC module. Connect the six enameled wires of the ESC to the motherboard as shown in the image:

![Screenshot_20240814_175757_com.hihonor.photos_edit_1604843523345038.png] The connection is shown in the image:

![Screenshot_20240814_180658_com.hihonor.photos_edit_1605165271599967.jpg] Then, shorten the two power cables of the ESC according to the distance and connect them to the motherboard. (Ensure a reliable connection!)

![Screenshot_20240814_181225_com.hihonor.photos.png] Finally, connect the screen. As shown in the picture, the first pin is GND, and the remaining three are soldered in order.

![Screenshot_20240814_182708_com.hihonor.photos_edit_1606393204433092.png] At this point, the circuit part of this project is complete. Place the screen facing the direction shown in the picture, and then connect the battery (pay attention to the positive and negative terminals! Connecting it backwards will burn it out!). Press and hold the power button for three seconds to turn it on:

![Screenshot_20240814_183421_com.hihonor.photos.png] The PWM is not compatible during the first power-on; the speed range needs to be matched.
Setting the speed range:
1. Turn off the machine.
2. Plug in the charger. The machine will display a power-on icon
. 3. Immediately press and hold the power button. The power-on icon screen will pause for a longer time, followed by a special ESC setting tone after the ESC power-on tone.
4. Release the button. The screen will enter the normal charging interface. Wait for the ESC setting tone to end. The speed range setting is complete.
Next, print the machine casing. There are two documents (it is recommended to print them separately and set the button cover height to 0.1mm and the hole expansion to 0.4mm). Install them according to the pictures in the product description above. Then use soft glue (hot melt glue, silicone, glass glue, double-sided tape) to glue the casing to the battery compartment.

![Screenshot_20240814_185600_com.hihonor.photos.png] Also, you can wrap the ESC with tape during installation for a neater look!

[Screenshot_20240814_190014_com.hihonor.photos.png] At this point, the process is basically complete. However, the ESC has a default 10-minute inactivity alarm, which will cause the motor to keep making noise during charging. Therefore, the ESC parameters need to be adjusted.
This requires using a C8051 emulator or other devices with a C2 interface to connect to the ESC for parameter adjustment.
Connect the GND/V3.3/ck/cd interface of the fan debugging port
(there is a string of letters next to the debugging interface, GVPKDRT, which stands for GNDV3.3PWMCKCDRXTX)
. 1. Open the BLHeliSuite software
. 2. Select the Toolstick device (the software usually recognizes it automatically)
. 3. Click Read Setup to read the ESC parameters.
A pop-up window as shown in the image appears, indicating a successful connection

. [capture_20240814194258567.jpg] 4. Adjust the three parameters circled in red in the image below to the parameters shown in the image. Leave the others unchanged.
(The first is the power-on volume, the second is the alarm volume, and the third is the alarm time. If you are interested, you can go to CSDN, where there are detailed tutorials for other parameters. Keywords: "blheli parameter tuning")
5. Click Write Setup to write the ESC parameters.
Parameter tuning is complete.

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(5) Video tutorial
[Mini duct is open source! - Bilibili] https://b23.tv/DsD4rNN

(6) Join the QQ group for technical support:
General group: 439994627
Second group: 882184460
Third group: 374838945
Fourth group: 328881202
(7) Update notes
August 15, 2024 update:
The three pads with the tag number GVPKDRT, RS, and OLED1 do not need to be purchased. These three are just solder pads. You'll also need to purchase 2.54mm pitch, 3.5mm plastic height female headers separately; you can find them on Taobao.
August 19, 2024 Update:
Added the necessary tool "USB to TTL Downloader".
Added a link to a video tutorial.