This text goals to exhibit the design of a sensible brightness-controlled lamp with a movement sensor utilizing a programmable mixed-signal matrix with 4 outputs, working voltage as much as 13.2 V, and a couple of A present per output. The system is created utilizing excessive voltage macrocells and different inside and exterior elements throughout the chip to work together with a movement sensor.
The lamp has two modes: the intensity-controlled and the night time mode. Within the intensity-controlled mode, the sunshine turns into brighter when the ambient mild decreases and vice versa. Within the night time mode, the brightness is consistently dim. The sunshine activates solely when the movement is detected by the PIR movement sensor. The lamp is powered with 3 AAA batteries (in complete 4.5 V) and it has a crimson LED blinking sign to inform about batteries discharging. The design can be utilized as extra lighting in residential homes and enterprise areas similar to hallway and storage.
Development and working precept
- Block diagram
The block diagram is proven in Determine 1.
Determine 1 The block diagram highlights the design constructing blocks of a brightness-controlled lamp. Supply: Renesas
The entire design file created in free GUI-based Go Configure Software program Hub is offered on GP file.
- Mode Choose
The design consists of six major elements.
The primary one is Mode Choose Change. The primary a part of the design is proven in Determine 2.
Determine 2 Right here is how the Mode Choose Change appears like. Supply: Renesas
The Mode Choose Change is LOW till urgent the button. Then the sign goes to DFF1, the place the sign is latched earlier than the subsequent urgent. So, Mode Choose has two states: LOW and HIGH, that are modified by urgent the button.
Then, the sign goes to Mode Choose half (Determine 3).
Determine 3 The picture reveals the Mode Choose half. Supply: Renesas
When the Mode Choose is low, the output of LUT3 is the output of Depth Managed Mode, when the Mode Choose is excessive, the output of LUT3 is the output of Evening Mode.
- Evening Mode
The Evening Mode is a steady PWM sign with the obligation cycle of ~12.5% and 64 Hz frequency (Determine 4).
Determine 4 The Evening Mode employs a steady PWM sign. Supply: Renesas
- Depth Managed Mode
The design of the Depth Managed Mode is proven in Determine 5.
Determine 5 Right here is how Depth Managed Mode appears like. Supply: Renesas
The thought is to create a Schmitt set off oscillator utilizing PIN 2, PIN 3, inverter, and a resistor. On this case, the ten M (darkish resistance) photoresistor is used as an alternative. It signifies that the frequency of the oscillator is dependent upon the worth of the resistance. When the ambient mild will increase, the resistance decreases, and when it turns into darker, the resistance will increase. Accordingly, when the resistance will increase, the frequency decreases, and vice versa.
Then, this sign is used as knowledge for the one-shot macrocell (CNT4).
Because the clock at 8.3 MHz and the inverted one-shot pulse width at 10.9 us are fixed, the output sign leads to PWM with a continuing 10.9 us of LOW and the remaining interval of HIGH, relying on the frequency generated by the Schmitt set off oscillator with a photoresistor.
- LED driver
When the Mode is chosen, the LUT3 output sign goes to HV OUT CTRL to drive the 6 LEDs linked in parallel. It’s configured as half-bridge in Pre-Driver Mode (Determine 6) to offer the mandatory present of 120 mA.
Determine 6 Six LEDS are linked in parallel on this mode. Supply: Renesas
- Movement sensor
The lamp has a PIR movement sensor to decrease energy consumption. The configuration might be seen in Determine 7.
Determine 7 The picture highlights the configuration wherein PIR movement sensor is used. Supply: Renesas
The CNT1 counts 30 seconds of movement sensor output. When the sensor output is LOW, greater than 30 seconds, HV OUT CTRL and oscillators are powered down with a HIGH sleep sign (see Determine 8).
Determine 8 That is how the oscillators configuration appears like. Supply: Renesas
- Battery discharge notification
Because the lamp is powered by 3 batteries of 1.5 V (4.5 V), the system wants a battery discharge notification which helps the person to not overlook to vary batteries. The configuration might be present in Determine 9. The analog comparator CMP0 with 0.5 achieve compares VDD and reference voltage. If this voltage is smaller than 1,952 mV, it’s time to change batteries as a result of the voltage has already decreased to three.9 V. On this case, the crimson LED begins blinking with a 25% obligation cycle notifying about discharge.
Determine 9 The picture reveals the configuration for battery discharge notification. Supply: Renesas
The total circuit design might be seen in Determine 10.
Determine 10 Right here is how full circuit design for battery discharge notification appears like. Supply: Renesas
Machine testing
To check the design, the circuit is linked to five V (VDD, VDD_A, and VDD_B).
The oscilloscope screenshots present the Schmitt set off oscillator sign (PIN 2, GPIO 0) in blue and the Depth Managed Mode output (PIN 7, HV_GPO0_HD) in yellow in Determine 11 to Determine 15.
As might be seen from these figures, the obligation cycle of Depth Managed Mode will increase (decreases) when the interval of Schmitt set off oscillator will increase (decreases).
Determine 11 Interval of the Schmitt set off oscillator quantities to 12.2 us. Supply: Renesas
Determine 12 Interval of the Schmitt set off oscillator quantities to 16.9 us. Supply: Renesas
Determine 13 Interval of the Schmitt set off oscillator quantities to twenty.65 us. Supply: Renesas
Determine 14 Interval of the Schmitt set off oscillator quantities to 29.45 us. Supply: Renesas
Determine 15 Interval of the Schmitt set off oscillator quantities to 55.9 us. Supply: Renesas
The outcomes show that the circuit works as anticipated, and the chip used is able to performing because the management module for LEDs.
Creating a sensible lamp
The article describes configure the HVPAK chip to create a sensible brightness-controlled lamp with movement sensor. It really works solely when the movement is detected and has two modes. The Evening Mode has a continuing low brightness. The Depth Managed Mode varies relying on the ambient mild. As well as, the good lamp has a battery discharge notification.
The inner assets within the SLG47105 chip, together with the oscillators, logic, and GPIOs, are straightforward to configure to implement the specified performance for this design.
Irena Antoniuk is technical documentation apps engineer at Renesas Electronics.
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