BitScope Smart Port Interface
BitScope Smart Port Interface
Ever since the original design, BitScope has had a Smart Port socket for connecting analog and digital signals to its inputs and outputs. This interface also provides power, ground and control for a connected circuit and most models provide waveform and clock generator signals too.
The Smart Port Interface was originally designed using a DB-25 connector but we switched to IDC-26 and current models use this new standard.
Every BitScope provides access to at least two analog inputs, 8 logic inputs, power and ground lines. The interface has general purpose control signals which can be used to control connected circuits or switch logic and most models include a waveform generator.
A common use for the Smart Port Interface to connect a logic POD like LP103X or an active differential probe such as DP01. The probe or POD is directly powered and controlled by the BitScope via this interface.
However, the Smart Port Interface can be used in many other ways, as Breadboard One demonstrates.
This is an example of how an entire prototype circuit can be powered, controlled and monitored by a BitScope (i.e. BS10 here) directly via the Smart Port Interface without the need for any other probes or accessories.
The pin connections of the BitScope Smart Port are:
| PIN | SIGNAL | DESCRIPTION |
| 1 | Vcc | Raw positive power supply; +12V for externally powered BitScope models and +5V for USB powered ones. It can supply between 200mA and 500mA depending on the model and BitScope power source. |
| 2 | Vdd | Regulated positive power supply; +7.5V or +5V for externally powered BitScope models and +3.3V for USB power ones. It can supply between 50mA and 150mA depending on the model. |
| 3, 5 | CH-A, CH-B | Analog Channel A and B. All models. 1MΩ/10pF input impedance (BS10) or 100kΩ/5pF other models. |
| 4, 6 | CH-C, CH-D | Analog Channel C and D. BS4xx models only, otherwise ground. |
| 7, 8 | IO-O, IO-I | General Purpose and/or Serial I/O signals. |
| 9, 11, 13, 15, 17, 19, 21, 23 | D-7, D-6, D-5, D-4, D-3, D-2, D-1, D-0 | Digital/Logic channel inputs. 100kΩ input impedance. All models. |
| 10, 12, 14, 16, 18, 20, 22, 24 | GND | Digital Grounds. Interleaved with the signals for convenient ribbon cable connection. |
| 25 | Vss | Regulated negative power supply; -7.5V or -5V for externally powered BitScope models and GND for USB power ones. It can supply about 100mA. |
| 26 | GEN | Waveform and clock generator output. 50Ω output impedance. |
The analog channel inputs on the Smart Port Interface are in addition to the BNC inputs on the front panel of BitScope (except BS10 which has no BNC inputs). They share the same analog capture channels but it's possible to alternate capture between the BNC and POD inputs on each channel to double the analog channel capacity of these models when data logging.
BitScope Smart Port Schematic | BS1xx Models
Logic inputs are protected from over-voltage (to 12V) with 470R series resistors as can been in the schematic. The Vcc rail includes polyfuse protection agains't short circuits and the analog inputs are similarly protected. The I/O control lines can be used to monitor or program externally connected microcontroller based circuits and the power ground lines can power small external circuits. Some models can even a provide negative rail for bipolar analog circuits.