Online programming is favored by many users due to its advantages of integrated programming and testing. However, it often suffers from instability and high programming failure rates due to long wiring caused by connection fixtures and clamps. How can we improve this?
Figure 1: Online Programming Fixture
1Increase Shielding Layer to Prevent Electromagnetic and Static Interference
The programmer, as a tool that closely communicates with the chip, is sensitive to electromagnetic interference. The programming environment is generally a factory workshop with high-power equipment, leading to significant electromagnetic interference. To reduce this interference, we can add shielding nets to the programming lines or choose cables with shielding functions, such as shielded cables or network cables. Additionally, it is best to wear anti-static gloves during operation to prevent static interference.
2Select Wires with Strong Conductivity
The integrity of signal transmission is related to the material, length, and thickness of the wire. Choosing thicker wires with better conductivity can reduce internal resistance and signal loss, such as using pure copper wires, gold-plated wires, or silver-plated wires.
Figure 2: Metal Resistivity
3Reduce Communication Frequency
Communication frequency is an important parameter for information transmission; the higher the frequency, the faster the transmission speed. However, signal attenuation increases with frequency and rapidly weakens with increased transmission distance. Therefore, when wiring is long, it is advisable to lower the communication frequency to enhance stability.
4Add Pull-up or Pull-down Resistors on Key Signal Lines
Some chip programming interfaces have weak driving capabilities and require appropriate pull-up or pull-down resistors to enhance driving ability. For instance, IIC and SWIM interfaces need strong pull-up resistors on the data lines, while automotive key chips like PCF79xx and NCF29xx require pull-down resistors on the clock lines.
5Select Programmers with Strong Driving Capability
The driving capability of the programmer’s pins directly affects the length of the wiring. Some online programmers available in the market directly expose the IO ports of the internal control chip or FPGA as programming signal inputs and outputs, which have weak driving capabilities. When the user’s wiring is relatively long (generally greater than 30cm), signal distortion can occur, leading to programming instability.
When selecting a programmer, it is essential to choose a professional online programmer, such as the P800isp programmer from ZLG Zhiyuan Electronics, which enhances the programmer’s driving capability through multi-channel signal amplification processing, solving a series of issues related to long wiring.
Figure 3: Comparison of Waveforms between P800isp and Some Programmers
ZhiYuan Electronics Introduction
Guangzhou ZhiYuan Electronics Co., Ltd. was established in 2001 and is a nationally recognized high-tech enterprise, as well as a research and development center for high-end industrial control measurement instruments in Guangdong Province.
Vision:To Become a Leading Enterprise in the Industrial Internet Ecosystem
We design high value-added modules, boards, and high-end measurement instruments using the “Chip + AWorks Software Platform”. By connecting to the ZWS IoT cloud through wired and wireless interfaces, we achieve big data processing and form an industrial internet ecosystem.
Mission:To Promote the Progress of China’s Industrial Internet with Leading Technology
Values:Professionalism and Focus Achieve Dreams