Freelance projects

Freelance projects

Integrate the payment system via QR code with the MQTT server through API

C & C++, Java — incorrectly specified categories?

179 USD

Client's review of cooperation with Serhii-Ivan Kulinyak

Integrate the payment system via QR code with the MQTT server through API

179 USD

The project was not completed within the established deadline.

2.6

Serhii Zaharchenko

3 November 2025

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Project Meta. There will be several devices with a QR code, the customer scans this code with a smartphone, it redirects to the payment system. After payment by card, the deducted amount should be received by the device. The device receives data via the MQTT protocol. Task for the developer. It is necessary to connect the payment system with our MQTT server via API. After payment via QR code, the system should read the MQTT topic (check for internet availability), if the topic is 1 (controller is connected) then transmit the information to another topic with the amount deducted from the customer. The ability to add new devices with a QR code is required.

Proposals 5

Please select

Andrey K.

1 287 1

Budget: 10000 UAH Deadline: 7 days

Hello. I have experience with Mqtt. I am ready to implement the backend in Node.js.

Serhii-Ivan Kulinyak

Winning proposal

2 1

Projects -
Rating -
Rating 993

Budget: 8000 UAH Deadline: 12 days

I can complete this project. I have experience with Java (Spring Boot, MQTT, integration with payment APIs), and I can also implement a faster option in Python (FastAPI + paho-mqtt). I will implement QR code generation, payment processing, and data transmission to MQTT topics with device connection verification.

Valentin Zaychenko

0 0

Projects -
Rating -
Rating 247

Budget: 8000 UAH Deadline: 5 days

Good day.

I have over 20 years of experience working on commercial projects. I can develop such a system for you in Python or C++, feel free to contact me.

Andrii Lyulchenko

7 1

Budget: 5000 UAH Deadline: 5 days

Good day. I am ready to discuss the project in more detail. I have work experience.

Ihor Rumyantsev

10 0

Projects 10
Rating -
Rating 1 470

Budget: 12000 UAH Deadline: 20 days

I can create such a system for you, message me privately!
Message me privately, I am ready to complete any task.

Serhii Zaharchenko
Ukraine

Projects 5
Rating 4.4
Rating 224