electrical: Several sources: for every combination that can be present at once – USB, battery, a programming cable, a host port – which source feeds which net? Does any of them feed back into a host port, a cell or another supply, also through a MOSFET body diode or a diode inside a module? What happens in the switch-over gap? LIM.backfeed holds the simulated scenarios (sim.json combine_sources), HINT.two_supplies names the nets two supplies meet on, LIM.range and LIM.v hold the transient runs – ask for the switch-overs and unplugs no run covers.
electrical: MCU pin functions: does every signal sit on a pin that has its function – PWM channel, SPI, I2C or UART instance, ADC input? Do PWM signals of independent frequencies sit on different PWM slices or timers? Is every pin used brought out on the module's header? Do errata touch the pins used? REQ.function holds the nets that state fn; a net without fn or a pin without functions it does not see.
electrical: Supply range and input levels of every IC that is not the MCU: is its minimum operating voltage met on its net, do VIH and VIL fit the domain that drives its inputs? LIM.v holds the absolute maximum, LIM.range and LVL.threshold the operating range and levels of every part whose entry gives them – ask for the parts without them, and for the power nets sim.json copper does not list.
electrical: Read-back of synchronous outputs: on which clock edge does a shift register or driver chain change its serial output, against the edge the MCU samples on in the SPI mode it uses? HINT.readback asks it for every output the MCU reads from a part whose inputs it also drives.
electrical: Minimum load of a supply: does a power bank stay on at the least current the board draws – firmware idle, radio off, LEDs dark? LIM.i holds every source with i_min_a, at i_core_min_a where the MCU's entry gives it – ask for it where an MCU's current swings.
electrical: Junction and touch temperature: for every part that dissipates – a conducting diode or body diode, a linear regulator, a resistor at its limit – its junction temperature, and its surface where a person can reach it. LIM.t holds every part whose entry gives rth_ja_k_per_w – ask for the parts without it.
regulatory: Scope: what private, gift or sale means for this board – placing on the market, making available. A board built for oneself still has to keep frequency law and must not be dangerous; in Germany it must meet the EMC requirements in substance – EMVG § 6 covers putting into service and passing on, a radio product FuAG § 7 – without the formalities of a sale. A gift is placing on the market under REACH (Art. 3(12): free of charge too), so Art. 33 applies: name a substance of very high concern above 0.1 % to a consumer who asks (45 days) – the suppliers' SVHC statements (compliance.reach) are needed for it (handbook 15.1); PARTS.fact/reach names every part without one.
regulatory: Substances: RoHS status of every part with its source; REACH SVHC statements; a part without a statement is open.
regulatory: Batteries: chemistry, protection, and for a board that is sold removability, labelling and the duties of whoever places it on the market.
regulatory: Supply: mains voltage on the board (low voltage directive), a power supply that comes with the product (its own conformity), USB power.
regulatory: A product that is sold: product safety and EMC, the EU declaration of conformity, the technical file, the CE marking, the manufacturer's name and address, the registrations (electrical equipment, packaging, batteries), and rules for connected products from the date they apply.
regulatory: Children: if the notes say children use it, whether it is a toy.
pcb: Exposed pads: under every part with a thermal or exposed pad – regulators, drivers, QFN packages – the copper the datasheet's thermal figure assumes, the vias into an inner or the other layer (count, drill, tented or filled against solder wicking), and the paste aperture that keeps the part from floating; LIM.t rests on rth_ja_k_per_w, a figure for the datasheet's copper (HINT.thermal_copper).
audio
About
speakers, amplifiers and analog signal paths: bridge-tied outputs, stable gain, hum, switching noise
electrical: Ground and returns: one return point for the audio path; large currents (the amplifier's supply, motors, LEDs) not returning under an input's reference; loops through USB or mains earth (HINT.audio_ground).
electrical: Supply of the amplifier: its peak current at full power against the supply and its local decoupling; a load step in a transient run shows the dip (steps).
electrical: Signal levels: every stage's bias inside its op-amp's ranges (LIM.range/opamp), the output's headroom at full signal, the input's level against the ADC's window where it is converted (LIM.range/adc).
cables
About
cables between boards and to the world: wire resistance and inductance, signal lines on leads, pins at their ends
electrical: Each cable: its length and gauge (length_m, awg or mm2 – the drop and the inductance the simulation sees), what is on it, and what a short or a discharge at its far end reaches (REQ.missing/leave).
electrical: Plugged while powered: the inrush and the LC spike of a supply lead – a transient run with the plug-in and the cable's l_nh_per_m shows it.
guitar
About
guitar pedals and instrument electronics: input loading, stable gain, battery and supply, the player's ground
electrical: The instrument input: the load the pickup or piezo sees – bias resistors, a tuner branch and the first stage in parallel – against what it needs (REQ.value/instrument, net load_min_ohm), an input high-pass, a series resistor against ESD at the jack.
electrical: Bias of discrete stages: transistor stages across the spread of hFE and of the JFETs' IDSS and VGS(off) – the simulation takes the entry's values, not their spread; ask for the worst part.
electrical: DC where signals are switched: both sides of a footswitch, relay contact or pot at the same DC level in every state, else it pops (LVL.undefined/analog finds a node without a DC path).
mains
About
hazardous voltage on the board: recognised by LIM.hazardous, not checked – spacing, isolation and the mains input are the reviewers' and the standard's
Suggested by
hazardous True
Reviewers' questions
electrical: Every net LIM.hazardous names: where the hazardous voltage comes from, what guards an ordinary person against it (enclosure, insulation, a bought and certified supply), and whether the board can do without it – a certified external supply that hands the board only safety extra-low voltage.
electrical: The mains input, where there is one: fuse, the X and Y capacitors, a varistor, and the discharge of capacitors across the line after unplugging – none of it is checked by edakit.
pcb: Spacing between the hazardous nets and everything a person can touch or that leaves the board: creepage and clearance per IEC 62368-1 or IEC 60664-1 for the voltage, pollution degree and insulation grade – edakit measures none of it.
regulatory: A board with hazardous voltage that is sold: which standard applies (IEC 62368-1, IEC 61010-1, IEC 60335-1), the Low Voltage Directive, and whether the product needs a test lab – the regulatory review (M-6) names it, edakit does not check it.
motors
About
motors, solenoids and heaters: start and stall current, returned energy, a second interruption for a heater
electrical: Start and stall: the current V / R of each winding against its driver, its supply and the wiring, and the dip it leaves on the MCU's supply. A transient run with the start as a load step (steps) shows the brown-out (LIM.range); ask for the cases no run covers – several motors starting at once, a stalled axis.
electrical: Returned energy: where does a braking motor or a switched-off coil put its energy – a clamp, the bulk capacitor, the supply? Behind a series diode the motor supply rises (HINT.motor_supply).
electrical: A heater: its power at the upper end of the supply (V² / R), the switch's dissipation at that current, and the second, independent interruption (HINT.heater).
power
About
batteries, cells, chargers and converters: polarity of the inputs, cell current, enable, thermal copper
electrical: Cells: the current each cell delivers in every state against its continuous and pulse limits (sim.json cells i_max_a, LIM.i/cell); a radio pulse from a coin cell as a load step in a transient run.
electrical: Charging: what feeds the load while a charger charges – a charger whose battery terminal feeds the load never ends its charge (HINT.power_path names a load on the cell without a power path); the charge current against the cell's limit (LIM.backfeed holds i_charge_max_a); the end of charge and the protection IC's release and delays, which no run shows (HINT.charge_termination, HINT.protection_timing).
electrical: Polarity: every plug that can go in the wrong way round marked reversible, so that PATH.reverse sees it (HINT.input_polarity).
radio
About
parts that transmit: their e.i.r.p. and bands against the EU licence-exempt bands, purpose.radio
regulatory: Radio: every part that transmits – bands and power against the EU's licence-exempt bands (the power as e.i.r.p.: conducted power plus antenna gain; edakit check compares it with the band's limit where that is an e.i.r.p., LIM.eirp), the module's own conformity, and what the product needs on top when it is sold. A module made for another region's band is a block. An ESP32 that transmits Wi-Fi: ask for the line in the firmware that sets an EU country with 802.11d off after every Wi-Fi start – esp_wifi_set_country_code("DE", false), the radio off if it fails (handbook 15.2); with true the station takes the country its access point announces – JP opens channel 14. What the firmware has to keep – channels, the country and 802.11d, the transmit power – is graded by the purpose (handbook 15.4): a note for a board built for oneself or given away, important for one that is sold, a block only where the hardware cannot be made to comply.
pcb: Antenna areas: for every part with a printed or chip antenna, the copper of this board under and around it on every layer – pours, tracks, vias, parts – and where the antenna sits against the board edge, as the module maker's layout guide asks; GEO.keepout holds the area an entry gives (antenna.keepout_mm) and, where the entry gives antenna.edge_mm, the antenna at the board edge – ask for the radios edakit check --coverage lists without them, and for the clearance beside the antenna and inside the housing (Espressif: at least 15 mm).
usb
About
USB-C receptacles and modules or breakouts with one: CC termination, data in both orientations
electrical: What an off-board module brings: a plugged-in module or breakout is a black box in the graph – its USB-C CC resistors, its VBUS diode or fuse, its regulator. What does each mean for the board: termination, a back-feed path, a second regulator on a rail? REQ.missing:cc holds the termination of a module's receptacle from values.usb_c.cc; the VBUS path and the regulator no code sees. A board bought and wired on a cable belongs in the graph as a board with bought = true (handbook 4.5).
