Can I solder Jumper Wires directly to the Pins of RX-2B microchip?

Hi everyone I am in great depression I need help anyone who can help me involving this project, my project is an rc car controlled through a PC, my program seems to be working fine through the arduino mega but am not getting any signal through the rc car, my rc car involves RX-2B microchip in my program i referred : Left, Right, Forward, Reverse, GND, in my rc car pcb board i need to solder this pins can i directly solder over the pins I may of soldered the wrong place before i will attach word document photos of the rc car board below please help anyone out there please.

GT3772 Blue Muscle 40MHz RC Car PCB Board Overview.zip (1.24 MB)

I had a look at several circuit diagrams online, and it seems the relevant IC pins are switched to ground. I would use small NPN transistors to do that. One across each button.

Collector to the relevant IC pin. Emitter to ground. 1k resistor to base.

Solder a wire to the other side of the 1k resistors. Those wires can go to Arduino's digital outputs. Don't forget to join the grounds. Leo..

Hi Wawa, as you mention use small NPN transistors across each button so i have 4 buttons forward, reverse, left and right do I need to buy 4 transistors, and will I have to use separate breadboard for this?

You can solder wires to the buttons, and bring them out to a breadboard for the four transistors and four resistors. Or you can solder the transistors to the buttons. Small NPN transistors (BC547, 2N3904 etc.) are the size of a match head, and will probably fit inside your remote. Only solder transistors if you have decent soldering skills. If you can mount the transistors inside the remote, then you won't need a breadboard. The remote, with the added transistors, will still function normally. Maybe you could fit a 5-pin connector on the box. Four inputs and a ground. Leo..

Thanks Wawa still working on it