Semiconductor triple-quantum dots (TQDs) are a promising platform for scalable quantum information processing, but the community has so far lacked access to affordable and flexible high-speed control electronics. SpinQICK, an open-source spin qubit-control package built on the Xilinx Radio Frequency System-on-Chip (RFSoC), directly addresses this gap by leveraging the high sampling-rate signal generation and advanced digital signal processing (DSP) capabilities of the Quantum Instrumentation Control Kit (QICK) to enable precise time-domain voltage control and readout of semiconductor spin qubits. In this paper, we use spinQICK to demonstrate coherent control, state preparation, and readout of a fully connected triangular exchange-only device. We also introduce and experimentally verify a novel dynamical decoupling (DD) sequence enabled by the triangular TQD and leverage its unique decoupling properties to characterize electrical noise. These results establish spinQICK as a low-cost, flexible platform for semiconductor spin qubit control and provide a pathway for hardware optimization through qubit-level noise diagnostics.